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  <TITLE>Common Markup for micropayment per-fee-links: a W3C Public Working
  Draft</TITLE>
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  <A href="http://www.w3.org/"><IMG height="48" width="72" alt="W3C" src="http://www.w3.org/Icons/w3c_home"></A>
  <H1>
    Common Markup for micropayment per-fee-links
  </H1>
  <H2>
    W3C Working Draft 25 August 1999
  </H2>
  <DL>
    <DT>
      This version:
    <DD>
      <A HREF="http://www.w3.org/TR/1999/WD-Micropayment-Markup-19990825">http://www.w3.org/TR/1999/WD-Micropayment-Markup-19990825</A>
    <DT>
      Latest version:
    <DD>
      <A HREF="http://www.w3.org/TR/Micropayment-Markup">http://www.w3.org/TR/Micropayment-Markup</A>
    <DT>
      Previous versions:
    <DD>
      <A HREF="http://www.w3.org/TR/1999/WD-Micropayment-Markup-19990609">http://www.w3.org/TR/1999/WD-Micropayment-Markup-19990609</A>
    <DD>
      <A HREF="http://www.w3.org/TR/1999/WD-Micropayment-Markup-19990315">http://www.w3.org/TR/1999/WD-Micropayment-Markup-19990315</A>
    <DT>
    <DT>
      Editor:
    <DD>
      Thierry Michel (<A HREF="mailto:tmichel@w3.org">tmichel@w3.org</A>)
  </DL>
  <P class="copyright">
  <A href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright"><BR>
  Copyright</A> &copy; 1999 <A href="http://www.w3.org/">W3C</A>
  (<A href="http://www.lcs.mit.edu/">MIT</A>,
  <A href="http://www.inria.fr/">INRIA</A>,
  <A href="http://www.keio.ac.jp/">Keio</A>), All Rights Reserved. W3C
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  use</A> and
  <A href="http://www.w3.org/Consortium/Legal/copyright-software">software
  licensing</A> rules apply.
</DIV>
<P>
  <HR title="Separator from Header">
<H2>
  <A name="abstract">Abstract</A>
</H2>
<P>
This specification provides an extensible way to embed in a Web page all
the information necessary to initialize a micropayment (amounts and currencies,
payment systems, etc). This embedding allows different micropayment electronic
wallets to coexist in a interoperable manner.
<H2>
  <A name="status">Status of this document</A>
</H2>
<P>
The
<A HREF="http://www.w3.org/ECommerce/Micropayments/Group/MarkupWG.html">Micropayment
Markup Working Group</A> (W3C Members only), with this 1999 August 25th Final
Public Working Draft, invites comment on our specification for "Common Markup
for Micropayment per-fee-links". <BR>
This Working Group is part of the
<A HREF="http://www.w3.org/ECommerce/Micropayments/Overview.html">Micropayment
task</A> within
the&nbsp;<A HREF="http://www.w3.org/ECommerce/Activity.html">ECommerce
Activity</A>.
<P>
The W3C Membership and other interested parties are invited to review this
public specification and report implementation experience. Please send comments
to the publicly archived
list&nbsp;<A HREF="mailto:www-micropay-comments@w3.org">www-micropay-comments@w3.org</A>
(<A HREF="http://lists.w3.org/Archives/Public/www-micropay-comments/">archive</A>).<BR>
<BR>
This specification is in
<A HREF="http://www.w3.org/Consortium/Process/#RecsWD">last call</A>, comments
from the Team and the Working Groups &nbsp;are requested before 30th September
1999. <BR>
However this final Public Working Draft will be held at this stage to await
significant implementation experience, allow possibly related work in other
Micropayment WGs to progress further, and collect comments on the public
mailing list.<BR>
The amount of implementation received by 2000 March 31th on the mailing list
will determine if this draft &nbsp;will be submitted for Proposed Recommendation
is to occur. In that case, comments will be considered for a new Proposed
Recommendation version that will follow very soon after.
<P>
While we welcome implementation experience reports, the Micropayment Markup
Working Group will not allow early implementation to constrain its ability
to make changes to this specification prior to final release .
<P>
This Working &nbsp;Draft may be updated, replaced, or obsoleted by other
documents at any time. It is inappropriate to use W3C Working Drafts as reference
material or to cite them as other than "work in progress". <BR>
A list of current W3C working drafts can be found at
<A HREF='http://www.w3.org/TR'>http://www.w3.org/TR</A>.
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<H2>
  <A name="contents">Table of contents</A>
</H2>
<OL CLASS="level0">
  <LI>
    <A HREF="#introduction">Introduction</A>
    <OL CLASS="level1">
      <LI>
	<A HREF='#origin-goals'>Origin and Goals</A>
      <LI>
	<A HREF='#Relationship'>Current status</A>
      <LI>
	<A HREF='#Principles'>Principles and Parties</A>
    </OL>
  <LI>
    <A HREF='#Architecture'>Architecture</A>
    <OL CLASS="level1">
      <LI>
	<A HREF='#Basic'>Basic architecture</A>
      <LI>
	<A HREF="#Security">Security</A>
    </OL>
  <LI>
    <A HREF='#Requirements'>Requirements</A>
    <OL CLASS="level1">
      <LI>
	<A HREF="#Conformancerec">Conformance Requirements</A>
      <LI>
	<A HREF="#Embedingrec">Embedding Requirements</A>
    </OL>
  <LI>
    <A HREF='#Requiredfields'>Defined fields</A>
    <OL CLASS="level1">
      <LI>
	<A HREF='#fields'>Fields description</A>
	<OL CLASS="level2">
	  <LI>
	    <A HREF="#Price">Price</A>
	  <LI>
	    <A HREF="#Textlink">Text and Image to be linked</A>
	  <LI>
	    <A HREF="#Request">Requesturl</A>
	  <LI>
	    <A HREF="#Client">Buyid</A>
	  <LI>
	    <A HREF="#Specific">Specific field</A>
	  <LI>
	    <A HREF="#title">Title</A>
	  <LI>
	    <A HREF="#Description">Longdesc</A>
	  <LI>
	    <A HREF="#Base">Baseurl</A>
	  <LI>
	    <A HREF="#Merchant">Merchant Identifier</A>
	  <LI>
	    <A HREF="#Duration">Duration</A>
	  <LI>
	    <A HREF="#Expiration">Expiration</A>
	  <LI>
	    <A HREF="#Target">Target</A>
	  <LI>
	    <A HREF="#Language">Language</A>
	  <LI>
	    <A HREF="#Type">Type</A>
	  <LI>
	    <A HREF="#AccessKey">AccessKey</A>
	  <LI>
	    <A HREF="#Chacarter Encoding">Character Encoding</A>
	  <LI>
	    <A HREF="#Meta">ExtData</A>
	  <LI>
	    <A HREF="#ExtDataParm">ExtDataParm</A>
	</OL>
      <LI>
	<A HREF="#General">General notes on fields</A>
    </OL>
  <LI>
    <A HREF="#Implementation">Implementation</A>
  <LI>
    <A HREF="#appendix">Appendices</A>
    <OL CLASS="level1">
      <LI>
	<A HREF="#Appendix 1">Embedding information in HTML pages-Encoding for Plug-in
	or Applets</A>
      <LI>
	<A HREF="#Appendix 2">Embedding information using RDF encoding</A>
      <LI>
	<A HREF="#Appendix 3">Generate Embedding on the Server side</A>
      <LI>
	<A HREF="#Appendix 4">Detecting the Browser capabilities</A>
      <LI>
	<A HREF="#Appendix 5">Generate Encoding using Javascript on the client side</A>
      <LI>
	<A HREF="#Appendix 6" NAME="List">List of payment systems</A>
      <LI>
	<A HREF="#Appendix 7" NAME="List">Currency naming</A>
    </OL>
  <LI>
    <A HREF="#acknowledgments">Acknowledgments</A>
  <LI>
    <A HREF='#References'>References</A>
</OL>
<P>
  <HR>
<H2>
  <A NAME="introduction">1. Introduction</A>
</H2>
<H3>
  <A NAME='origin-goals'>1.1 Origin and Goals</A>
</H3>
<P>
Micropayments provide an alternative revenue source for content providers
(initially of text and pictures, presumably multimedia later on) beyond
advertising and subscriptions. Micropayments may also provide revenue streams
for service providers (database lookup, proxy services etc.).
<P>
Currently, there is no clear definition of a "Web micropayment" that encompasses
all systems claiming to be micropayment systems. However, these systems all
share the goal of minimizing the cost overhead of a single transaction. Most
of these micropayment systems try to save costs, including financial
risk-management costs, operational costs (including communication, processing,
storage), and set-up costs.<BR>
Most micropayment systems also try to provide a simple user interface, especially
making buying as easy as possible. We believe that to pay a small amount
for content or services, the user should use the same user interface metaphor
as for regular web content: just click on a hypertext link. <BR>
Namely, micropayment content shall be reached by clicking on special, new
sort of links, which we call per-fee-links. Many of the existing micropayment
systems do follow this approach, however each of them is using its own
proprietary method of creating a per-fee-link and encoding the vital information
in the per-fee-link.
<P>
This document proposes an extensible and interoperable way to embed in a
Web page all the information necessary to initialize a micropayment, and
in particular for encoding per-fee-links.
<H3>
  <A NAME='Relationship'>1.2 Current status</A>
</H3>
<P>
Today, a merchant willing to support multiple payment systems needs to embed
in each Web page payment information specific to each target system, using
a proprietary encoding for each one. Proprietary encodings introduce redundancy
of information and extra work for Web page authors. <BR>
This situation motivates the need for a common markup supported by multiple
payment systems.
<H3>
  <A NAME='Principles'>1.3 Principles and Parties</A>
</H3>
<P>
Micropayments involve a buyer/customer C, a vendor/merchant M, and potentially
one or more additional parties that keep accounts (usually called brokers
[in Millicent], billing servers [in IBM MicroPayments], intermediaries [in
France Telecom Micropayments], etc.). However in this document we focus only
on the flow from the merchant to the customer, involved in the initialization
of a micropayment.
<H2>
  <A NAME='Architecture'>2. Architecture</A>
</H2>
<P>
Parties involved in this specification architecture are Client and Merchant.
<P>
The Client initiates the micropayment when requesting information from the
server.
<H3>
  <A NAME='Basic'>2.1 Basic architecture </A>
</H3>
<P>
The basic architecture consist of:
<UL>
  <LI>
    On the Client side:
    <UL>
      <LI>
	a Browser,
      <LI>
	a module<I> </I>called Per Fee Link Handler (PFLH),
      <LI>
	one or more electronic micropayment wallets.<BR>
    </UL>
  <LI>
    On the Merchant side:
    <UL>
      <LI>
	an HTTP server<BR>
    </UL>
</UL>
<P class="center">
<IMG ALT="basic architecture:Server,PFLH,Wallet,Browser," SRC="architecture">
<P class="caption">
[1] Merchant HTTP Server to Per Fee Link Handler flow<BR>
[2] Per Fee Link Handler to Wallet and Wallet to Per Fee Link Handler flows
<P>
This document focuses on the Merchant server to Per Fee Link Handler-Browser
flow and specifies the payment markup information.
<P>
This document does not address:
<UL>
  <LI>
    Per Fee Link Handler to electronic Wallet and Wallet to Per Fee Link Handler
    flows,
  <LI>
    Per Fee Link Handler requirements.
</UL>
<P>
<STRONG>Note.</STRONG> <EM>The API from Per Fee Link Handler (PFLH) to Wallet
will be addressed in another specific API Working Draft. The PFLH functionalities
will also be addressed in another specific PFLH Working Draft.</EM>
<H3>
  <A NAME="Security">2.2 Security </A>
</H3>
<P>
This document specifies the encoding of per-fee-links inside HTML page sent
from the merchant to the consumers browser. The specification does not describe
the specific transport mechanism of the HTML page, although we expect that
HTTP will be used as it is the transport mechanism used by existing browsers.
In particular, the specification does not address security concerns related
to the transmission of the per-fee-link from merchant to client, such as
authentication of the parameters in the per-fee-link (such as price) and
confidentiality of the per-fee-link. If such security concerns exist, the
application SHOULD use appropriate mechanisms, e.g. protect the confidentiality
and authenticity of all communication between consumer and merchant using
the Secure Sockets Layer [<A HREF="#SSL">SSL</A>] (HTTPS) protocol.
<H2>
  3 <A NAME="Requirements">Requirements</A>
</H2>
<P>
This document section specifies requirements for interoperability among
micropayment systems.
<H3>
  3.1 <A NAME="Conformancerec">Conformance requirements</A>
</H3>
<P>
The words "MUST" (or "required"), "SHOULD" (or "recommended"), and "MAY"
(or "optional") are used throughout the document and should be read as
interoperability requirements. The words are used as defined in RFC2119
[<A HREF="#RFC2119">RFC2119</A>] for defining the significance of each particular
requirement.
<P>
An implementation conforms to this specification if it satisfies all of the
normative statements ("MUST" or "required") in this document.
<H3>
  3.2<A NAME="Embedingrec"> Embedding requirements:</A>
</H3>
<P>
Requirements for embedding micropayment information in web pages are:
<UL>
  <LI>
    Embedding MUST be simple, allowing "click and pay" interface,
  <LI>
    Embedding MUST minimize network-packet round trips,
  <LI>
    Embedding SHOULD use standard (or de-facto standard) features which are
    implemented by most currently available browsers.
  <LI>
    Embedding SHOULD be common to all micropayment schemes.
</UL>
<H2>
  <A NAME="Requiredfields"> 4. Defined fields </A>
</H2>
<H2>
  4.1 <A NAME="Field">Field description </A>
</H2>
<P>
All the following common fields MUST be provided for conformance:
&nbsp;<A href="#Price">price</A>, &nbsp;<A href="#Textlink">textlink</A>,
<A href="#Request">requesturl</A>, <A HREF="#Specific">payment system</A>.
<P>
In addition, there SHOULD be&nbsp;a <A HREF="#title">title</A> field.
There&nbsp;&nbsp;MAY be an <A href="#Imagelink">imagelink</A>,
<A href="#Client">buyid</A>, <A HREF="#Base">baseurl</A>,
<A HREF="#Description">longdesc</A>, <A href="#Merchant">merchantname</A>,
<A href="#Duration">duration</A>,&nbsp;<A href="#Expiration">expiration</A>,
<A HREF="#target">target</A>, <A HREF="#Language">hreflang</A>,
<A HREF="#Type">type</A>, <A HREF="#AccessKey">accesskey</A>,
&nbsp;<A HREF="#Chacarter Encoding">charset</A>, <A HREF="#Meta">ExtData</A>,
<A HREF="#ExtDataParm">ExtDataParm</A> and information that a
<A href="#Specific">specific</A> payment system requires.
<P>
<TABLE BORDER CELLPADDING="5">
  <CAPTION>
    Micropayment fields
  </CAPTION>
  <TR>
    <TH>Field name</TH>
    <TH>Short Description</TH>
    <TH>Format</TH>
    <TH>Requirements</TH>
  </TR>
  <TR>
    <TD><A href="#Price">price</A></TD>
    <TD>Specifies the default amount and currency that the Customer will be charged
      upon following the per-fee-link.</TD>
    <TD>character string</TD>
    <TD>MUST be provided</TD>
  </TR>
  <TR>
    <TD><A href="#Textlink">textlink</A></TD>
    <TD>Textual description of what the client is requesting. The text source
      of the per-fee-link.</TD>
    <TD>character string</TD>
    <TD>MUST be provided</TD>
  </TR>
  <TR>
    <TD><A href="#Imagelink">imagelink</A></TD>
    <TD>Graphical description of what the client is requesting. The graphic source
      of the per-fee-link. (here <TT>textlink</TT> provides a textual equivalent
      of the image for accessibility).</TD>
    <TD><A HREF="#URI">URI</A></TD>
    <TD>MAY be provided</TD>
  </TR>
  <TR>
    <TD><A href="#Request">requesturl</A></TD>
    <TD>Identifies what the client is actually requesting</TD>
    <TD><A HREF="#URI">URI</A></TD>
    <TD>MUST be provided</TD>
  </TR>
  <TR>
    <TD><A HREF="#Specific">payment system</A></TD>
    <TD>Identifies the micropayment systems supported by the merchant <BR>
      and can also provide information unique to each payment system</TD>
    <TD><A HREF="#URI">URI</A> <BR>
      character string</TD>
    <TD>MUST be provided<BR>
      MAY be provided</TD>
  </TR>
  <TR>
    <TD><A href="#Client">buyid</A></TD>
    <TD>Identifies the merchant offer the client is buying or has already bought</TD>
    <TD><A HREF="#URI">URI</A></TD>
    <TD>MAY be provided</TD>
  </TR>
  <TR>
    <TD><A HREF="#Base">baseurl</A></TD>
    <TD>Provides a common prefix for &nbsp;relative URIs (e.g. the <TT>buyid</TT>
      and <TT>requesturl</TT> parameters)</TD>
    <TD>absolute <A HREF="#URI">URI</A></TD>
    <TD>MAY be provided</TD>
  </TR>
  <TR>
    <TD><A HREF="#title">title</A></TD>
    <TD>Titles the content of the merchant offer the client is buying or has
      already bought</TD>
    <TD>character string</TD>
    <TD>SHOULD be provided</TD>
  </TR>
  <TR>
    <TD><A HREF="#Description">longdesc</A></TD>
    <TD>Describes in detail the content of the merchant offer the client is buying
      or has already bought</TD>
    <TD><A HREF="#URI">URI</A></TD>
    <TD>MAY be provided</TD>
  </TR>
  <TR>
    <TD><A href="#Merchant">merchantname</A></TD>
    <TD>Specifies a merchant designation</TD>
    <TD>character string</TD>
    <TD>MAY be provided</TD>
  </TR>
  <TR>
    <TD><A href="#Duration">duration</A></TD>
    <TD>Indicates the time after purchase any URIs with the same <TT>buyid</TT>
      can be retrieved without further payment.</TD>
    <TD>integer number</TD>
    <TD><SPAN >MAY</SPAN> &nbsp;be provided</TD>
  </TR>
  <TR>
    <TD><A href="#Expiration">expiration</A></TD>
    <TD>Indicates a date until which the offer from the merchant is valid.</TD>
    <TD>date/time string<BR>
      YYYY-MM-DDThh:mm:ssZ</TD>
    <TD>MAY be provided</TD>
  </TR>
  <TR>
    <TD><A HREF="#target">target</A></TD>
    <TD>Specifies the name of a frame where a document is to be loaded.</TD>
    <TD>character string</TD>
    <TD>MAY be provided</TD>
  </TR>
  <TR>
    <TD><A HREF="#Language">hreflang</A></TD>
    <TD>Specifies the base language of the resource designated by the per-fee-link.</TD>
    <TD>language codes</TD>
    <TD>MAY be provided</TD>
  </TR>
  <TR>
    <TD><A HREF="#Type">type</A></TD>
    <TD>Specifies the content type of &nbsp;the linked resource, designated by
      the per-fee-link.</TD>
    <TD>Mimetypes</TD>
    <TD>MAY be provided</TD>
  </TR>
  <TR>
    <TD><A HREF="#AccessKey">accesskey</A></TD>
    <TD>Assigns an access key to a per-fee-link.</TD>
    <TD>character string</TD>
    <TD>MAY be provided</TD>
  </TR>
  <TR>
    <TD><A HREF="#Chacarter Encoding">charset</A></TD>
    <TD>Specifies the character encoding of the resource designated by the
      per-fee-link.</TD>
    <TD>Charset</TD>
    <TD>MAY be provided</TD>
  </TR>
  <TR>
    <TD><A HREF="#Meta">ExtData</A></TD>
    <TD>Allows linking to an external metadata &nbsp;file describing additional
      information regarding the per-fee-link.</TD>
    <TD><A HREF="#URI">URI</A></TD>
    <TD>MAY be provided</TD>
  </TR>
  <TR>
    <TD><A HREF="#ExtDataParm">ExtDataParm</A></TD>
    <TD>Provides a parameter to be applied for interpreting the contents of the
      ExtData file.</TD>
    <TD>character string</TD>
    <TD>MAY be provided</TD>
  </TR>
</TABLE>
<P>
<H3>
  4.1.1 <A NAME="Price">Price</A>
</H3>
<P>
The <TT>price</TT> parameter, which takes a character string, specifies the
default amount and currency that the Customer will be charged upon following
the link (if not already paid for). However this price may be overridden
by the <A href="#Specific">specific</A> payment system with which the payment
is to be made. The character string MUST be encoded as an amount followed
by a currency unit as follows:
<UL>
  <LI>
    A number MUST precede the currency. <BR>
    This number MAY optionally be preceded by "+" or "-" specifying if it is
    a positive amount (amount Customer will pay) or negative (amount Customer
    will get). If absent, "+" is assumed. <BR>
    The integer portion of the number, a non-empty string of decimal digits,
    MUST be present, designating the quantity of major units of that currency.
    The fractional portion of the number MAY optionally follow the integer portion.
    This fractional part begins with a decimal point, indicated by a ".", followed
    by any number of decimal digits.
  <LI>
    The exponential scaling portion of the number MAY optionally follow. It MUST
    have an exponential "E" followed by either "+" or "-" and immediately followed
    by a non-empty integer scaling exponent. Any number of digits of precision
    and any size exponent MAY be provided. This scaling multiplies the number
    by the indicated power of ten.
  <LI>
    These currency codes are the three-letter ISO 4217 codes or unregistered
    four to ten letters currency names. (Refer to currencies naming in
    <A HREF="#Appendix 7">Appendix 7</A>)
</UL>
<P>
This <TT>price</TT> parameter is mandatory and MUST be provided unless
<A HREF="#Meta">ExtData</A> &nbsp;parameter is provided and the price is
specified there.
<H3>
  4.1.2 <A NAME="Textlink">Text</A> or <A NAME="Imagelink">Image</A> to be
  linked
</H3>
<P>
The <TT>textlink</TT> parameter, which takes a character string, provides
a textual description of what the client is requesting. It is the text source
of the per-fee-link.<BR>
This <TT>textlink</TT> parameter is mandatory and MUST be provided.
<P>
The <TT>imagelink</TT> parameter, which takes a <A HREF="#URI">URI</A>, provides
a graphical description of what the client is requesting. It is the graphic
source of the per-fee-link.<BR>
When using this <TT>imagelink</TT> &nbsp;parameter, the <TT>textlink</TT>
parameter provides a textual equivalent for the image and is necessary for
accessibility.
<H3>
  4.1.3 <A NAME="Request">Requesturl</A>
</H3>
<P>
The <TT>requesturl</TT> parameter, which takes a <A HREF="#URI">URI</A>,
identifies what the client is actually requesting through the current
per-fee-link. This requested url is a part of the merchant offer identified
by <TT>buyid</TT>. It can be either an absolute <A HREF="#URI">URI</A> or
relative <A HREF="#URI">URI</A> only if the <TT>baseurl</TT> parameter is
specified.&nbsp;(allowing the wallet to construct the final URL)<BR>
<BR>
This <TT>requesturl</TT> parameter is mandatory and MUST be provided.
<H3>
  4.1.4 <A NAME="Client">Buyid</A>
</H3>
<P>
The <TT>buyid</TT> parameter, which takes a <A HREF="#URI">URI</A>, identifies
the merchant offer the client is buying (or has already bought). It can be
either an absolute <A HREF="#URI">URI</A> or relative <A HREF="#URI">URI</A>
only if the <TT>baseurl</TT> parameter is specified.&nbsp;(allowing the wallet
to construct the final URL).<BR>
This parameter MAY be identical to the <TT>requesturl</TT> parameter. It
MAY be different if, for example, the client has purchased a collection of
pages and requests only one of these pages. In this case, the resource identified
by <TT>buyid</TT> is larger than that identified by <TT>requesturl</TT>
parameter.<BR>
A merchant offer has an associated set of <TT>requesturl</TT>'s, that is
a set of per-fee-links. <TT>requesturl</TT> are identifiers for per-fee-links.
Payment for the whole set is required when you first request one per-fee-link
of the set.<BR>
This <TT>buyid</TT> parameter is optional and MAY be provided. If it is omitted
we assume it is identical to <TT>requesturl</TT>.
<H3>
  4.1.5 <A NAME="Specific">Payment System Identifier and specific field</A>
</H3>
<P>
This specific field MUST be present in order to provide an identifier of
at least one usable payment system, and all suitable systems SHOULD be named.
&nbsp;When required, it MAY also provide parameters specific to each payment
system identified as mentioned above, insuring coexistence among the different
payment systems. Thus, there can be as many parameter sets &nbsp;(identifier
and specific parameters) as there are payments systems supported by the merchant.
<P>
The identifier for a payment system MUST be a <A HREF="#URI">URI</A>, unless
this payment system is registered (<A HREF="#Appendix 6">see Appendix 6</A>),
in which case the registered short name is to be used.<BR>
Additional specific information MAY be provided with a character string.<BR>
Information &nbsp;provided in the specific field SHOULD be used to override
information &nbsp;specified in the common fields above. To allow multiple
specific parameters, one MUST provide and use the following naming convention:
<UL>
  <LI>
    Specify the name of each payment system as name="1.mpname" value="xxx" where
    1 stands for the number of the payment system (1, 2, 3... as many as supported
    by merchant), xxx is the name of the payment system - either a URL or a name
    from a pre-assigned list (<A HREF="#Appendix 6">see Appendix 6</A>).
  <LI>
    Then the rest of parameters of system 1 (2,3,..) will be given as
    name="1.mpparamname" value="value", with a special parameter e.g.: name="1.mpurl"
    value="http://www.foo.org/" giving a location to learn &amp; register for
    that payment system.
</UL>
<P>
<STRONG>Note.</STRONG> We recommend that when a system uses specific parameters
for the same meaning as the common (non-specific) parameters defined above
in the specification, the same parameter name will be used e.g. name="1.mpprice",
name="1.mpbaseurl" &nbsp;and the same syntax if possible. Normally such a
parameter SHOULD override the common (non-specific) parameter.
<H3>
  4.1.6<A NAME="title"> Title </A>
</H3>
<P>
The <TT>title</TT> parameter, which takes a character string, titles the
resource of the merchant offer the client is buying or has already bought
(needed for registration in wallet log files for example).<BR>
This <TT>title</TT> parameter is optional but SHOULD be provided.
<H3>
  4.1.7<A NAME="Description"> Longdesc</A>
</H3>
<P>
The <TT>longdesc</TT> parameter, which takes a <A HREF="#URI">URI</A>, provides
a detailed description of the merchant offer the client is buying.<BR>
This <TT>longdesc</TT> parameter is optional and MAY be provided.
<H3>
  4.1.8 <A NAME="Base">Baseurl </A>
</H3>
<P>
The <TT>baseurl</TT> parameter specifies an absolute <A HREF="#URI">URI</A>
that acts as the base URI for resolving relative URIs (e.g. a prefix for
the <TT>buyid</TT> and <TT>requesturl</TT> parameters). <BR>
It identifies the merchant site where the purchase is to occur, plus a path
and a specific character string <TT>$MP$</TT> to be replaced by the wallet
by a proper payment system short code name. This search for $MP$ happens
before &nbsp;any unescaping of the URL is
done.&nbsp;(<A HREF="#Appendix 6">see Appendix 6</A>).
<P>
Examples of such a string are:
<PRE>http://www.merchant.org/shop/sales/$MP$/
http://www.$MP$.merchant.org/shop/sales/
</PRE>
<P>
This <TT>baseurl</TT> parameter is optional and MAY be provided.
<H3>
  4.1.9 <A NAME="Merchant">Merchant Site Identifier</A>
</H3>
<P>
The <TT>merchantname</TT> parameter, which takes a character string, allows
giving a merchant name designation. This optional &nbsp;parameter provides
a user-viewable version of the name of the merchant. The wallet will need
to validate this (to make sure this really corresponds to the merchant ID
in the payment system - MAY also use some specific parameter if needed).
<H3>
  4.1.10 <A NAME="Duration">Duration</A>
</H3>
<P>
The <TT>duration</TT> parameter, which takes an integer number of seconds,
indicates the time after purchase any URIs with the same <TT>buyid</TT> can
be retrieved without further payment.<BR>
This <TT>duration</TT> parameter <SPAN >MAY</SPAN> be provided. In case it
is not provided, a default value is set to zero (meaning that the per-fee-link
can be only retrieved once after purchase).
<H3>
  4.1.11 <A NAME="Expiration">Expiration </A>
</H3>
<P>
The <TT>expiration</TT> parameter, which takes a date and time, indicates
a date and time until which the offer from the merchant is valid. After this
given date and time the offer has expired and any attempt to buy it will
be rejected.
<P>
rejected<BR>
<SPAN >It is an optional parameter and MAY be provided.</SPAN>
<P>
The value of this parameter, a date/time string, MUST use the following format
as described in [<A HREF="#DATETIME">DATETIME</A>]:
<PRE>   YYYY-MM-DDThh:mm:ssTZD
</PRE>
<P>
This format includes the complete date (YYYY-MM-DD) separated from the time
&nbsp;by the letter (T), which MUST include hours (hh), minutes (mm), seconds
(ss) and a time zone designator (TZD) where TZD is restricted to Z. Times
are always expressed in UTC (Coordinated Universal Time), with the special
UTC designator ("Z"). <BR>
An example of such a string is "1999-11-05T13:15:30Z" <BR>
Please consult [<A HREF="#DATETIME">DATETIME</A>] for the meaning of each
field.
<H3>
  4.1.12 <A NAME="target">Target </A>
</H3>
<P>
The <TT>target</TT> parameter, which takes a character string, specifies
the name of a frame where a document is to be loaded.
<P>
By assigning a name to a frame via the name attribute, authors can refer
to it as the "target" of per-fee-links. Except for the reserved names listed
below, frame target names MUST begin with an alphabetic character (a-zA-Z).
User agents SHOULD ignore all other target names.<BR>
The following target names are reserved and have special meanings:
<UL>
  <LI>
    <TT> _blank</TT>: The user agent SHOULD load the designated document in a
    new, unnamed window.
  <LI>
    <TT>_self</TT>: The user agent SHOULD load the document in the same frame
    as per-fee-link that refers to this target.
  <LI>
    <TT>_parent</TT>: The user agent SHOULD load the document into the immediate
    FRAMESET parent of the current frame. This value is equivalent to _self if
    the current frame has no parent.
  <LI>
    <TT>_top</TT>: The user agent SHOULD load the document into the full, original
    window (thus cancelling all other frames). This value is equivalent to _self
    if the current frame has no parent.
</UL>
<P>
This <TT>target</TT> parameter is optional and MAY be provided. If not provided,
a default value is set to <TT>_self </TT>(meaning that the document &nbsp;will
load in the same frame as current per-fee-link).
<H3>
  4.1.13 <A NAME="Language">Language </A>
</H3>
<P>
The <TT>hreflang</TT> parameter identifies the language of &nbsp;the linked
resource. <BR>
[<A HREF="#RFC1766">RFC1766</A>] defines and explains the language codes
to be used. Briefly, language codes consist of a primary code and a possibly
empty series of subcodes: language-code = primary-code ( "-" subcode )*<BR>
Here are some sample language codes:<BR>
"en": English<BR>
"en-US": the U.S. version of English.<BR>
"en-cockney": the Cockney version of English.<BR>
"i-navajo": the Navajo language spoken by some Native Americans.<BR>
"x-klingon": The primary tag "x" indicates an experimental language tag
<P>
Two-letter primary codes are reserved for [<A HREF="#ISO639">ISO639</A>]
language abbreviations. Two-letter codes include fr (French), de (German),
it (Italian), nl (Dutch), el (Greek), es (Spanish), pt (Portuguese), ar (Arabic),
he (Hebrew), ru (Russian), zh (Chinese), ja (Japanese), hi (Hindi), ur (Urdu),
and sa (Sanskrit). Any two-letter subcode is understood to be a
[<A HREF="#ISO3166">ISO3166</A>] country code.
<P>
This <TT>hreflang</TT> parameter is optional and MAY be provided.
<H3>
  4.1.14 <A NAME="Type">Type</A>
</H3>
<P>
The <TT>type</TT> parameter specifies the content type of &nbsp;the linked
resource.<BR>
Examples of content types include "text/html", "image/png", "image/gif",
"video/mpeg", "audio/basic", "text/tcl", "text/javascript", and "text/vbscript".
For the current list of registered MIME types, please consult
[<A HREF="#MIMETYPES">MIMETYPES</A>].
<P>
This <TT>type</TT> parameter is optional and MAY be provided.
<H3>
  4.1.15 <A NAME="AccessKey">AccessKey</A>
</H3>
<P>
The <TT>accesskey</TT> parameter, which takes a character string, assigns
an access key to a per-fee-link. An access key is a single character from
the document character set.<BR>
Pressing an access key assigned to a per-fee-link gives focus to the
per-fee-link. When a user activates a per-fee-link, the user agent generally
follows the link.
<P>
Examples of such a string is:<BR>
accesskey="L".&nbsp;Typing this access key takes the user to the requested
document of the current per-fee-link.
<P>
This <TT>accesskey</TT> parameter is optional and MAY be provided.
<H3>
  4.1.16 <A NAME="Chacarter Encoding">Character Encoding</A>
</H3>
<P>
The <TT>charset</TT> parameter specifies the character encoding of the resource
designated by the per-fee-link, allowing conversion of &nbsp;a sequence of
bytes into a sequence of characters. Please consult the section on
<A HREF="http://www.w3.org/TR/REC-html40/charset.html#encodings">character
encodings</A> in the HTML4.0 Recommendation for more details.<BR>
Values must be strings (e.g., "euc-jp") from the [<A HREF="#IANA">IANA</A>]
registry (see [<A HREF="#CHARSETS">CHARSETS</A>] for a complete list). Names
of character encodings are case-insensitive.<BR>
An example of such a string is charset="ISO-8859-1"
<P>
This <TT>charset</TT> parameter is optional and MAY be provided.
<H3>
  4.1.17 <A NAME="Meta">ExtData</A>
</H3>
<P>
The <TT>ExtData</TT> &nbsp;parameter, which takes a <A HREF="#URI">URI</A>,
allows linking to an external metadata &nbsp;file describing additional
information regarding the per-fee-link.
<P>
Formats for this metadata file will be defined in future documents of this
group, and are likely to be expressed using the Resource Description Framework
([<A href="#RDF">RDF</A>]). This metadata file will typically express parameters
common to many per-fee-links such as currency conversion table, price-code
table (mapping from price code to price), general information and policy
of the seller, etc. The information may override parameters provided with
the per-fee-link (e.g. <A href="#Price">price</A>). <BR>
This <TT>ExtData</TT> parameter is optional and MAY be provided.
<H3>
  4.1.18 <A NAME="ExtDataParm">ExtDataParm</A>
</H3>
<P>
Provides a parameter to be applied for interpreting the contents of the ExtData
file. A typical example would be a price code, to be used as the entry into
a price-code table to provide the actual price.<BR>
This <TT>ExtDataParm </TT>parameter is optional, it MAY be provided but only
if <TT>ExtData</TT> is provided.
<P>
<H2>
  4.2 <A NAME="General">General notes on fields</A>
</H2>
<P>
<STRONG>Note.</STRONG> It is an error to provide:
<UL>
  <LI>
    multiple values of the same common (non-specific) parameter. &nbsp;
  <LI>
    a field &nbsp;which is not well structured &nbsp;as described above in this
    specification.
</UL>
<P>
In these cases response is undefined (preferably an error message - probably
done by browser.)
<P>
<STRONG>Note.</STRONG> Any common parameters provided in an external file
through the <TT>ExtData</TT> parameter SHOULD override information specified
in all the <A HREF="#Requiredfields">common parameters</A> above.<BR>
<BR>
<STRONG>Note.</STRONG> The parameters <A HREF="#Base">baseurl</A>,
<A href="#Request">requesturl</A> are passed by PFLH to the wallets, allowing
to construct the payment-system-specific URL for the merchandise (to be used
in the HTTP GET/POST back to the merchant server). These fields MAY be overruled
if necessary, by a payment-system specific <TT>baseurl</TT> parameter (e.g.
if different payment systems are on different web servers at the merchant).
<P>
The URL sent to the wallet &nbsp;identifies a merchant site where the purchase
is to occur, plus a path and a specific character string <TT>$MP$</TT> to
be replaced by the wallet by a proper payment system short code name
(<A HREF="#Appendix 6">see Appendix 6</A>).<BR>
<TABLE BORDER CELLPADDING="10">
  <CAPTION>
    Fields involved in final URL constructed by Wallet
  </CAPTION>
  <TR>
    <TD COLSPAN=3><TT>baseurl</TT> parameter</TD>
    <TD ><TT>requesturl</TT> parameter</TD>
  </TR>
  <TR>
    <TH>Merchant site</TH>
    <TH>Path</TH>
    <TH>Payment system</TH>
    <TH>URL suffix (Client Requested url)</TH>
  </TR>
  <TR>
    <TD>http://www.merchant.org/</TD>
    <TD>shop/sales/</TD>
    <TD>$MP$</TD>
    <TD>elvis.html</TD>
  </TR>
  <TR>
    <TD COLSPAN=4><STRONG>URL sent to Wallet:
      </STRONG>http://www.merchant.org/shop/sales/$MP$/elvis.html</TD>
  </TR>
  <TR>
    <TD COLSPAN=4><STRONG>Final URL constructed by Wallet for Payment Order :
      </STRONG>http://www.merchant.org/shop/sales/Micropay/elvis.html</TD>
  </TR>
</TABLE>
<P>
<H2>
  <A NAME="Implementation">5. Implementation </A>
</H2>
<P>
One of the main requirements expressed in this document is that embedding
micropayment information in HTML SHOULD work with all current browsers.<BR>
The Working Group has also required interoperability among micropayment systems
though a common Markup.
<P>
For current browsers, embedding information in HTML pages MUST be done using
a Per Fee Link Handler, which MUST &nbsp;be a plug-in or JAVA Applet.<BR>
This embedding MUST be done as described in
&nbsp;<A HREF="#Appendix 1">Appendix 1.</A>
<P>
Today most browsers are non-RDF-aware browsers, but we cite an example embedding
of micropayment information using Resource Description Framework
([<A HREF="#RDF">RDF</A>]) for future RDF-compliant user agents in
<A HREF="#Appendix 2">Appendix 2.</A>
<P>
In order to have this embedding using RDF to work with current browsers,
a "transformation engine" hosted on the server could transform the HTML document
linked and the RDF document into an HTML document that includes either OBJECT
or APPLET or EMBED elements, making it understandable by current browser
versions. This architecture is proposed for informational purposes in
<A HREF="#Appendix 3">Appendix 3</A>.
<P>
In order to send to the browser &nbsp;the proper HTML page (with OBJECT or
APPLET or EMBED elements) the Merchant server needs to know the capabilities
of this browser. Is the Browser JAVA enabled ? Is the &nbsp;right Plugin
installed in the browser ? etc. Solutions and code &nbsp;are &nbsp;proposed
for informational purposes in <A HREF="#Appendix 4">Appendix 4</A>.
<P>
An Alternative implementation is to generate the HTML page on the client
side using Javascript for example. After detection of the browser capabilities,
a script can generate the elements and attributes for each fee link.Solutions
and code &nbsp;are &nbsp;proposed in <A HREF="#Appendix 5">Appendix 5</A>.
<P>
  <HR>
<H2>
  <A name="appendix"><STRONG>Appendices</STRONG></A>
</H2>
<H2>
  <A NAME="Appendix 1">Appendix 1: Embedding micropayment information &nbsp;in
  HTML pages using encodings&nbsp;for Plug-ins or Applets.</A>
</H2>
<P>
Due to <A HREF="#Embedingrec">requirements expressed above</A>, embedding
micropayment information SHOULD use standard (or de-facto standard) features
which are implemented by most currently available browsers.
<P>
All requested information needed to start micropayment MUST be present in
the HTML page sent from the merchant server. <BR>
For current browsers, embedding information in HTML pages can be done using
a Per Fee Link Handler, which MUST either be a plug-in or JAVA Applet.
<P>
In order to allow the Per Fee Link Handler to process this information, it
SHOULD be stored in an OBJECT element.
<P>
For user agents that do not support the OBJECT element, and for reasons of
backward compatibility, authors MAY use the APPLET or EMBED element.
<STRONG><BR>
Note.</STRONG> The APPLET element is deprecated in HTML 4.0 and SHOULD be
avoided. The EMBED element is <STRONG>not</STRONG> part of a W3C Recommendation
and SHOULD be avoided. Authors SHOULD use the &nbsp;OBJECT element.
<H3>
  A1.1 OBJECT element
</H3>
<P>
HTML 4.0 introduced the OBJECT element (<A href="#HTML40">[HTML40]</A>, section
13.3) to allow HTML authors to specify everything required by an object for
its presentation by a user agent: source code, initial values, and run-time
data. The term "object" refers to applets, plug-ins, media handlers, etc.
<PRE>&lt;OBJECT codetype="application/java"
         classid="http://www.miamachina.org/applet/micropayment.class"&gt;<BR>&lt;PARAM name="duration" value="60" valuetype="data"&gt;
A per-fee-link that needs an applet for rendering
&lt;/OBJECT&gt;
</PRE>
<P>
The HTML 4.0 specification defines the attributes of the OBJECT element.
<BR>
The "classid" attribute specifies the location of the OBJECT's implementation
with a URL. <BR>
The "codetype" attribute specifies the content type of data to expect when
downloading the OBJECT. <BR>
The PARAM element within an OBJECT element specifies values to give to the
object at run-time (as name/value pairs).
<H3>
  A1.2 APPLET element
</H3>
<P>
For user agents that do not support the OBJECT element and for reasons of
backward compatibility, authors MAY use the APPLET element. HTML 3.2
([<A href="#HTML32">HTML32</A>]) introduced the APPLET element to allow designers
to embed a Java applet in an HTML document. It is supported by all Java-enabled
browsers, but has been <STRONG>deprecated</STRONG> in HTML 4.0 in favor of
the OBJECT element.
<PRE>&lt;APPLET codebase="http://www.miamachina.org/applet/"
        code="micropayment.class"
        archive="myclasses.jar,myaudio.jar"&gt;
     &lt;PARAM name="duration" value="60" valuetype="data"&gt;
A per-fee-link that needs an applet for rendering.
&lt;/APPLET&gt;
</PRE>
<P>
The HTML 4.0 specification (<A href="#HTML40">[HTML40]</A>, section 13.4)
defines the attributes of the (deprecated) APPLET element. <BR>
The "codebase" attribute specifies the base URL for the applet. <BR>
The "code" attribute specifies either the name of the class file that contains
the applet's compiled applet subclass or the path to get the class. <BR>
The "archive" attribute specifies a comma-separated list of URIs designated
resources to preload such as signed (trusted) code such as a Per Fee Link
Handler. <BR>
The PARAM element within an APPLET element specifies values to give to the
object at run-time (as name/value pairs).
<H3>
  A1.3 EMBED element
</H3>
<P>
For user agents that do not support the OBJECT element and for reasons of
backward compatibility, authors MAY use EMBED element. <STRONG><BR>
Note.</STRONG> Whenever the OBJECT element can be used, authors SHOULD avoid
EMBED because it is not defined by a W3C Recommendation.
<P>
This EMBED element, supported by all plug-in-enabled browsers, allows designers
to embed a plug-in in an HTML document.
<PRE>&lt;EMBED src="http://www.miamachina.org/MicropaymentPlugin.exe"
       duration="60"&gt;<BR>A per-fee-link that needs a plug-in for rendering.<BR>&lt;/EMBED&gt;
</PRE>
<P>
Optional parameters within EMBED element will be used to pass required
information by the plug-in at run-time.
<P>
PARAMETER_NAME=PARAMETER_VALUE
<H3>
  A1.4 Per Fee Link Handler for OBJECT, APPLET, and EMBED element.
</H3>
<P>
The PFL Handler is a module that can either be a plug-in or a Java Applet.<BR>
It could be implemented in Java 1.2 allowing signed JAVA applets in browsers
supporting it, and otherwise as a plug-in.
<P>
The Per Fee Link Handler (PFLH) functionalities will be addressed in a specific
Working Draft.
<H3>
  A1.5 Syntax for embedded <B>per-fee-link</B> using OBJECT, APPLET, and EMBED
  element.
</H3>
<P>
<B>The <TT><A HREF="#Base">Baseurl</A></TT>&nbsp;data field:</B>
<P>
For OBJECT and APPLET:
<PRE>
&lt;PARAM name="baseurl" value="http://www.merchant.org/shop"
valuetype="ref"&gt;<BR>&lt;PARAM name="merchantname" value="ShopAndPay" valuetype="data"&gt;
</PRE>
<P>
For EMBED:
<PRE>baseurl="http://www.merchant.org/shop"<BR>merchantname="ShopAndPay"
</PRE>
<P>
<B>The <TT><A HREF="#Client">ClientBuy</A></TT> data field:</B>
<P>
For OBJECT and APPLET:
<PRE>&lt;PARAM name="buyid" value="catalog.html" valuetype="ref"&gt;
</PRE>
<P>
For EMBED:
<PRE>buyid="catalog.html" <BR>
</PRE>
<P>
<B>The <TT><A HREF="#Request">ClientRequest</A></TT> data field:</B>
<P>
For OBJECT and APPLET:
<PRE>&lt;PARAM name="requesturl" value="elvis.html" valuetype="ref"&gt;
</PRE>
<P>
For EMBED:
<PRE>requesturl="elvis.html"
</PRE>
<P>
<B>The <TT><A HREF="#Textlink">textlink</A></TT> and<TT>
<A href="#Imagelink">imagelink</A></TT> data fields :</B><BR>
<BR>
For OBJECT and APPLET:
<PRE>&lt;PARAM name="textlink" value="Buy the biography of Elvis"
valuetype="data"&gt;
&lt;PARAM name="imagelink" value="http://www.merchant.org/product.gif"
valuetype="ref"&gt;
</PRE>
<P>
For EMBED:
<PRE>textlink="Buy the biography of Elvis"
imagelink="http://www.merchant.org/product.gif"
</PRE>
<P>
<B>The <TT><A HREF="#Price">Price</A></TT> data field:</B><BR>
<BR>
For OBJECT and APPLET:
<PRE>&lt;PARAM name="price" value="+0.01USD" valuetype="data"&gt;
<I>statement for one cent of a US Dollar.</I>
</PRE>
<P>
For EMBED:
<PRE>price="+1E-2FRF"
<I>statement for one cent of a French Franc</I>.
</PRE>
<P>
<B>The <TT><A HREF="#Longdesc">Title</A></TT> data field:</B>
<P>
For OBJECT and APPLET:
<PRE>&lt;PARAM name="title" value="Biography of Elvis"
  valuetype="data"&gt;
</PRE>
<P>
For EMBED:
<PRE>title="Biography of Elvis"
</PRE>
<P>
<B>The <TT><A HREF="#Duration">Duration</A></TT> data field</B><BR>
<BR>
For OBJECT and APPLET:
<PRE>&lt;PARAM name="duration" value="60" valuetype="data"&gt;
</PRE>
<P>
For EMBED:
<PRE>duration="60"
</PRE>
<P>
<B>The <TT><A HREF="#Expiration">Expiration date</A> </TT>data field:</B>
<P>
For OBJECT and APPLET:
<PRE>&lt;PARAM name="expiration" value="1999-11-05T13:15:30Z"
valuetype="data"&gt;
</PRE>
<P>
<I>corresponds to November 5, 1999, 8:15:30 am, GMT Time.</I>
<P>
For EMBED:
<PRE>expiration="1999-11-05T13:15:30Z"
</PRE>
<P>
<I>corresponds to the same instant as above.</I>
<P>
<B>For data fields <TT><A HREF="#Specific">specific</A></TT> to a micropayment
system:</B>
<P>
For OBJECT and APPLET:
<PRE>&lt;PARAM name="1.mpname" value="micropayment"
       valuetype="data"&gt;
&lt;PARAM name="1.mpurl" value="http://www.foo.it/micropay"
       valuetype="ref"&gt;
&lt;PARAM name="1.specific" value="124rfdetg14ft58rdef21f4251"
       valuetype="data"&gt;
&lt;PARAM name="1.mpbaseurl" value="http://www.merchant.it/"
       valuetype="ref"&gt;

<BR>&lt;PARAM name="2.mpname" value="millipayment"
       valuetype="data"&gt;
&lt;PARAM name="2.mpurl" value="http://www.foo.it/millipay"
       valuetype="ref"&gt;
&lt;PARAM name="2.specific" value="475rdg546tfeww12wcft254hy4"
       valuetype="data"&gt;
&lt;PARAM name="2.mpbaseurl" value="http://www.merchant.fr/"
       valuetype="ref"&gt;


</PRE>
<P>
For EMBED:
<PRE>1.mpname="micropayment"
1.mpurl="http://www.foo.it/micropay"<BR>1.specific="124rfdetg14ft58rdef21f4251"
1.mpbaseurl="http://www.merchant.it/"

2.mpname="millipayment" <BR>2.mpurl="http://www.foo.it/millipay"
2.specific="475rdg546tfeww12wcft254hy4"
2.mpbaseurl="http://www.merchant.fr/"<BR>
</PRE>
<H3>
  A1.6 &nbsp;HTML example of embedded per-fee-link using OBJECT element.
</H3>
<PRE>
&lt;HTML&gt;&lt;HEAD&gt;
&lt;TITLE&gt;Example:Fee Link for an Java Applet PFLH using OBJECT element<BR>&lt;/TITLE&gt;&lt;/HEAD&gt;
&lt;BODY&gt;
&lt;OBJECT codetype="application/java"
        classid="http://www.miamachina.org/applet/micropayment.class"&gt;
&lt;PARAM name="baseurl" value="http://www.merchant.org/shop"
       valuetype="ref"&gt;<BR>&lt;PARAM name="merchantname" value="ShopAndPay" valuetype="data"&gt;
&lt;PARAM name="buyid" value="catalog.html" valuetype="ref"&gt;
&lt;PARAM name="requesturl" value="elvis.html" valuetype="ref"&gt;
&lt;PARAM name="textlink" value="Buy the biography of Elvis"<BR>       valuetype="data"&gt;
&lt;PARAM name="price" value="+0.01USD" valuetype="data"&gt;<BR>&lt;PARAM name="title" value="Biography of Elvis"<BR>       valuetype="data"&gt;
&lt;PARAM name="duration" value="60" valuetype="data"&gt;
&lt;PARAM name="expiration" value="1999-11-05T13:15:30Z"<BR>       valuetype="data"&gt;
<BR>&lt;PARAM name="1.mpname" value="micropayment"
       valuetype="data"&gt;
&lt;PARAM name="1.mpurl" value="http://www.foo.it/micropay"
       valuetype="ref"&gt;
&lt;PARAM name="1.specific" value="124rfdetg14ft58rdef21f4251"
       valuetype="data"&gt;
&lt;PARAM name="1.mpbaseurl" value="http://www.merchant.it/"
       valuetype="ref"&gt;

<BR>&lt;PARAM name="2.mpname" value="millipayment"
       valuetype="data"&gt;
&lt;PARAM name="2.mpurl" value="http://www.foo.it/millipay"
       valuetype="ref"&gt;
&lt;PARAM name="2.specific" value="475rdg546tfeww12wcft254hy4"
       valuetype="data"&gt;
&lt;PARAM name="2.mpbaseurl" value="http://www.merchant.fr/"
       valuetype="ref"&gt;
A per-fee-link that needs an applet for rendering.
&lt;/OBJECT&gt;
&lt;/BODY&gt;&lt;/HTML&gt;<BR>
</PRE>
<H3>
  A1.7 &nbsp;HTML example of embedded per-fee-link using APPLET element.
</H3>
<PRE>
&lt;HTML&gt;&lt;HEAD&gt;
&lt;TITLE&gt;Example:Fee Link for an Java Applet PFLH using APPLET element<BR>&lt;/TITLE&gt;&lt;/HEAD&gt;
&lt;BODY&gt;
&lt;APPLET codebase="http://www.miamachina.org/applet/"
        code="micropayment.class"
        archive="myclasses.jar,myaudio.jar"&gt;
&lt;PARAM name="baseurl" value="http://www.merchant.org/shop"
       valuetype="ref"&gt;<BR>&lt;PARAM name="merchantname" value="ShopAndPay" valuetype="data"&gt;
&lt;PARAM name="buyid" value="catalog.html" valuetype="ref"&gt;
&lt;PARAM name="requesturl" value="elvis.html" valuetype="ref"&gt;
&lt;PARAM name="textlink" value="Buy the biography of Elvis"<BR>       valuetype="data"&gt;
&lt;PARAM name="price" value="+0.01USD" valuetype="data"&gt;<BR>&lt;PARAM name="title" value="Biography of Elvis"
<BR>       valuetype="data"&gt;
&lt;PARAM name="duration" value="60" valuetype="data"&gt;
&lt;PARAM name="expiration" value="1999-11-05T13:15:30Z"<BR>       valuetype="data"&gt;
<BR>&lt;PARAM name="1.mpname" value="micropayment"
       valuetype="data"&gt;
&lt;PARAM name="1.mpurl" value="http://www.foo.it/micropay"
       valuetype="ref"&gt;
&lt;PARAM name="1.specific" value="124rfdetg14ft58rdef21f4251"
       valuetype="data"&gt;
&lt;PARAM name="1.mpbaseurl" value="http://www.merchant.it/"
       valuetype="ref"&gt;
<BR>&lt;PARAM name="2.mpname" value="millipayment"
       valuetype="data"&gt;
&lt;PARAM name="2.mpurl" value="http://www.foo.it/millipay"
       valuetype="ref"&gt;
&lt;PARAM name="2.specific" value="475rdg546tfeww12wcft254hy4"
       valuetype="data"&gt;
&lt;PARAM name="2.mpbaseurl" value="http://www.merchant.fr/"
       valuetype="ref"&gt;
A per-fee-link that needs an applet for rendering.
&lt;/APPLET&gt;
&lt;/BODY&gt;&lt;/HTML&gt;<BR>
</PRE>
<H3>
  A1.8 &nbsp;HTML example of embedded per-fee-link using EMBED element.
</H3>
<PRE>&lt;HTML&gt;&lt;HEAD&gt;
&lt;TITLE&gt;Example:Fee Link for a Plugin PFLH using EMBED element<BR>&lt;/TITLE&gt;&lt;/HEAD&gt;
&lt;BODY&gt;
&lt;EMBED src="http://www.miamachina.org/MicropaymentPlugin.exe"
baseurl="http://www.merchant.org/shop"
merchantname="ShopAndPay"
buyid="catalog.html"
requesturl="elvis.html"
textlink="Buy the biography of Elvis"
price="+0.01USD"<BR>title="Biography of Elvis"<BR>duration="60"
expiration="1999-11-05T13:15:30Z"
<BR>1.mpname="micropayment"
1.mpurl="http://www.foo.it/micropay"<BR>1.specific="124rfdetg14ft58rdef21f4251"
1.mpbaseurl="http://www.merchant.it/"

2.mpname="millipayment" <BR>2.mpurl="http://www.foo.it/millipay"
2.specific="475rdg546tfeww12wcft254hy4"
2.mpbaseurl="http://www.merchant.fr/" &gt;<BR>A per-fee-link that needs a plug-in for rendering.<BR>&lt;/EMBED&gt;
&lt;/BODY&gt;&lt;/HTML&gt;
</PRE>
<H3>
  A1.9 &nbsp;HTML example of embedded per-fee-link using OBJECT element and
  metadata file.
</H3>
<PRE>
&lt;HTML&gt;&lt;HEAD&gt;
&lt;TITLE&gt;Example:Fee Link for an Java Applet PFLH using OBJECT element and ExtData field<BR>&lt;/TITLE&gt;&lt;/HEAD&gt;
&lt;BODY&gt;
&lt;OBJECT codetype="application/java"
        classid="http://www.miamachina.org/applet/micropayment.class"&gt;
&lt;PARAM name="ExtData" value="http://www.merchant.org/shop/<TT>Micropayment-perfeelinks.rdf</TT>"
       valuetype="ref"&gt;
&lt;PARAM name="price" value="+0.01USD" valuetype="data"&gt;<BR>A per-fee-link that needs an applet for rendering.
&lt;/OBJECT&gt;
&lt;/BODY&gt;&lt;/HTML&gt;
</PRE>
<P>
In this last example the <TT>ExtData</TT> parameter allows linking to external
metadata describing this per-fee-link. On retrieval of the RDF file, the
Java applet parses this file and extracts the common micropayment fields
(e.g. <A href="#Price">price</A>, &nbsp;<A href="#Textlink">textlink</A>,
<A href="#Request">requesturl</A>, <A HREF="#Specific">payment system</A>,
<A HREF="#title">title</A>, <A href="#Imagelink">imagelink</A>,
<A href="#Client">buyid</A>, <A HREF="#Base">baseurl</A>,
<A HREF="#Description">longdesc</A>, <A href="#Merchant">merchantname</A>,
<A href="#Duration">duration</A>,&nbsp;<A href="#Expiration">expiration</A>,
etc.).<BR>
Refer to <A HREF="#Appendix 2">Apendix 2</A>&nbsp;for examples using RDF
encoding.
<P>
<STRONG>Note.</STRONG><EM> </EM>Information &nbsp;provided in this
<TT>ExtData</TT> parameter SHOULD be overriden by &nbsp;information
&nbsp;specified in all the <A HREF="#Requiredfields">common parameters</A>
above. <BR>
So in this example, the price mentioned in the PARAM element will override
any price mentioned in the RDF file.
<H2>
  <A NAME="Appendix 2">Appendix 2: Embedding micropayment information using
  RDF encoding .</A>
</H2>
<P>
This embedding using &nbsp;the Resource Description Framework
([<A href="#RDF">RDF</A>]) is an example implementation allowing different
micropayment electronic wallets to coexist in a interoperable manner.<BR>
All the <A HREF='#Requiredfields'>Required fields</A> are stated above in
this document.
<H3>
  A2.<B>1 Benefits with RDF encoding:</B>
</H3>
<P>
Micropayment information can be embedded in HTML pages using RDF to be processed
by RDF-compliant user agents.<BR>
Micropayment information are statements that are properly expressed according
to the Resource Description Framework ([<A href="#RDF">RDF</A>]). There are
a number of reasons to use RDF as a data format for micropayments:
<UL>
  <LI>
    Shared code: Using an open format results in easy implementation through
    use of code libraries,
  <LI>
    Searchability: RDF is designed for queries and searches (e.g. "Give me all
    the pictures of &nbsp;Van Gogh that I can buy using micropayments for less
    than 1 EUR") ,
  <LI>
    Extensibility with respect to micropayments,
  <LI>
    Integration with other relevant meta-information,
  <LI>
    Scalability: The power of this markup method grows with the power of RDF.
</UL>
<P>
As metadata, the information for micropayments can thereby be reasoned upon,
and fully integrated with all the other information stored in &nbsp;the World
Wide Web.
<H3>
  A2.<B>2 RDF Transport:</B>
</H3>
<P>
In order to fully exploit these benefits, it is suggested that the necessary
parameters for micropayments are encoded in RDF and shipped by one or more
of the following ways:
<OL>
  <LI>
    External from the content, linked (in the case of HTML files with the LINK
    element). We recommend using the link relation type
    ([<A href="#HTML40">HTML40</A>], section 6.12) of "meta" for this purpose.
    For example:<BR>
    <TT>&lt;LINK rel="meta" href="Micropayment-links.RDF"&gt;</TT>
  <LI>
    Included in the content of a Web in the section of the HTML document (inside
    the HEAD element).
  <LI>
    Together with the content in the HTTP headers.
</OL>
<P>
<BR>
The recommended technique for embedding RDF expressions in an HTML document
([<A href="#RDF">RDF</A>], Appendix B.) is simply to insert the RDF in-line.
<P>
<STRONG>Note.</STRONG><EM> The resulting document will no longer conform
to HTML specifications up to and including [<A href="#HTML40">HTML40</A>],
but the W3C anticipates that the HTML language will evolve to support this.
See current &nbsp;new [<A HREF="#XHTML">XHTML</A>] work.</EM>
<H3>
  A2.<B>3 RDF Model:</B>
</H3>
<P class="Center">
<IMG ALT="The RDF model using nodes and arcs diagram" SRC="RDFfeelink">
<P class="caption">
Figure 1: The RDF model (nodes and arcs diagram).
<P>
<STRONG>Note.</STRONG><EM> </EM>The prose corresponding to this diagram could
be read as follows :<BR>
<I>The per-fee-link (#feelink-1) whose price is one centime of FRF, requesturl
is "elvis.html", buyid is "catalog.html", longdesc is "description.html",
baseurl is "http://www.merchant.org/shop/", duration is 60 seconds and expiration
date is 1999-11-05T13:15:30Z, has alternative payment systems - identified
by name "AlternativePaymentSystems".<BR>
The first payment system is called "micropay1". It has a name
"http://www.foo.it/micropay1" and a value "xxxxxxxxxxxxxxxxxxxx".<BR>
The second payment system is called "micropay2". It has a name
"http://www.foo.it/micropay2" and a value "yyyyyyyyyyyyyyyyyyyy".</I>
<P>
<H3>
  A2.<B>4 Example of </B>per-fee-link <B>using RDF encoding :</B>
</H3>
<H4>
  A2.4.1 Text or image to be linked :
</H4>
<P>
The per-fee-link is specified with the A element from HTML 4.0.
<P>
For a text to be linked, the <TT>textlink</TT> parameter is in this case
the content of the A element. <BR>
The &nbsp;"id" attribute is used to assign a unique identifier to the A
element.<BR>
The <TT>requesturl</TT> parameter is the value of the "href" attribute of
the A element, identifying the source anchor. It could be either a relative
or absolute URL.<BR>
The <TT>title</TT> parameter is the value of the "title" attribute of the
A element.<BR>
The <TT>hreflang</TT> parameter is the value of the "hreflang" attribute
of the A element.<BR>
The <TT>accesskey</TT> parameter is the value of the "accesskey" attribute
of the A element.<BR>
The <TT>charset </TT>parameter is the value of the "charset" attribute of
the A element.<BR>
The <TT>target </TT>parameter is the value of the "target" attribute of the
A element.
<PRE>&lt;BODY&gt;
&lt;A href="elvis.html" id="feelink-1"
title="Biography of Elvis"
accesskey="L" charset="ISO-8859-1" type="text/html"
hreflang="en-US" target="_blank"&gt;
Buy the Biography of Elvis through this Per-fee-link &lt;/A&gt;
&lt;/BODY&gt;
</PRE>
<P>
For an image to be linked, the per-fee-link is specified using the A and
IMG elements of HTML. <BR>
The <TT>imagelink</TT> parameter is the value of the "src" attribute of IMG
element and in this case the <TT>textlink</TT> parameter is the value of
the "alt" attribute of IMG element.
<PRE>&lt;BODY&gt;
&lt;A href="elvis.html" id="feelink-img1"
title="Biography of Elvis"&gt;
&lt;IMG src="http://www.merchant.org/product.gif"
     alt="Buy the Biography of Elvis through this Per-fee-link"&gt; &lt;/A&gt;
&lt;/BODY&gt;
</PRE>
<P>
The following <A NAME="RDFstatements">RDF statements </A>describing this
per-fee-link are mentioned in the HEAD of the HTML document as follows:
<P>
a- <B>Basic Serialization Syntax :</B>
<P>
The specification of RDF uses the Extensible Markup Language [XML] encoding
as its interchange syntax. RDF also requires the XML namespaces facility
to precisely associate each property with the schema that defines the property;
see Section 2.2.3., Schemas and Namespaces.
<P>
When a fragment of RDF is incorporated into an HTML document some browsers
will render any exposed string content. Exposed string content is anything
that appears between the "&gt;" that ends one tag and the "&lt;" that begins
the next tag.
<PRE>&lt;HEAD&gt;
&lt;TITLE&gt;Example of Fee Link - Basic Serialization RDF Syntax Encoding&lt;/TITLE&gt;<BR>&lt;rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:mp="http://www.w3.org/schema/micropay#"&gt;
&lt;rdf:Description about="#feelink-1"&gt;
  &lt;mp:price&gt;1E-2FRF&lt;/mp:price&gt;
  &lt;mp:baseurl rdf:resource="http://www.merchant.org/shop"/&gt;
  &lt;mp:buyid rdf:resource="catalog.html"/&gt;
  &lt;mp:requesturl rdf:resource="elvis.html"/&gt;
  &lt;mp:longdesc rdf:resource="description.html"/&gt;
  &lt;mp:duration&gt;60&lt;/mp:duration&gt;
  &lt;mp:expiration&gt;1999-11-05T13:15:30Z&lt;/mp:expiration&gt;
  &lt;mp:paymentsystem&gt;
    &lt;rdf:Alt&gt;
       &lt;rdf:li&gt;
	&lt;rdf:Description ID="micropay1"&gt;
	  &lt;rdf:type resource="http://www.w3.org/schema/micropay#paymentoption"/&gt;
	  &lt;mp:name rdf:resource="http://www.foo.it/micropay1"/&gt;
	  &lt;rdf:value&gt;xxxxxxxxxxxxxxxxxx&lt;/rdf:value&gt;
	&lt;/rdf:Description&gt;
       &lt;/rdf:li&gt;
       &lt;rdf:li&gt;
	&lt;rdf:Description ID="micropay2"&gt;
	  &lt;rdf:type resource="http://www.w3.org/schema/micropay#paymentoption"/&gt;
	  &lt;mp:name rdf:resource="http://www.foo.it/micropay2"/&gt;
	  &lt;rdf:value&gt;yyyyyyyyyyyyyyyyyyyy&lt;/rdf:value&gt;
	&lt;/rdf:Description&gt;
       &lt;/rdf:li&gt;
    &lt;/rdf:Alt&gt;
  &lt;/mp:paymentsystem&gt;
&lt;/rdf:Description&gt;
&lt;/rdf:RDF&gt;
&lt;/HEAD&gt;

</PRE>
<P>
<B>b-Basic Abbreviated Syntax</B>
<P>
While the serialization syntax shows the structure of an RDF model most clearly,
often it is desirable to use a more compact XML form. The RDF abbreviated
syntax accomplishes this.
<P>
The RDF abbreviated syntax can frequently be used to write property values
that are strings in attribute form and leave only white space as exposed
content.
<P>
The following RDF abbreviated syntax is equivalent to the above Basic
Serialization Syntax.
<PRE>
&lt;HEAD&gt;
&lt;TITLE&gt;Example of Fee Link - Abbreviated RDF Syntax Encoding&lt;/TITLE&gt;
&lt;rdf:RDF
  xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
  xmlns:mp="http://www.w3.org/schema/micropay#"&gt;
  &lt;rdf:Description about="#feelink-1"
    mp:price="1E-2FRF"
    mp:duration="60"
    mp:expiration="1999-11-05T13:15:30Z"&gt;
    &lt;mp:baseurl rdf:resource="http://www.merchant.org/shop"/&gt;
    &lt;mp:buyid rdf:resource="catalog.html"/&gt;
    &lt;mp:requesturl rdf:resource="elvis.html"/&gt;
    &lt;mp:longdesc rdf:resource="description.html"/&gt;
    &lt;mp:paymentsystem&gt;
      &lt;rdf:Alt&gt;
        &lt;rdf:li&gt;
          &lt;mp:paymentoption rdf:ID="micropay1" name="http://www.foo.it/micropay1"
          rdf:value="xxxxxxxxxxxxxxxxxx"/&gt; &lt;/rdf:li&gt;
        &lt;rdf:li&gt;
          &lt;mp:paymentoption rdf:ID="micropay2" name="http://www.foo.it/micropay2"
          rdf:value="yyyyyyyyyyyyyyyyyy"/&gt; &lt;/rdf:li&gt;
      &lt;/rdf:Alt&gt;
    &lt;/mp:paymentsystem&gt;
  &lt;/rdf:Description&gt;<BR>&lt;/rdf:RDF&gt;<BR>&lt;/HEAD&gt;

</PRE>
<P>
<STRONG>Note.</STRONG><EM> </EM>Authors concerned about preventing their
RDF content from rendering in old browsers MAY use the abbreviated syntax
to move the property value into an attribute.<BR>
The above RDF Description MAY be external to the HTML document but linked
with an LINK element and supplied by the transfer mechanism in the same retrieval
transaction as that which returns the resource ("along-with"; e.g. with HTTP
GET or HEAD). The RDF file would be a separate URI .This would allow the
base HTML document to be cacheable.
<P>
Validate the above RDF description with
&nbsp;<A HREF="http://www.w3.org/RDF/Implementations/SiRPAC/">SiRPAC</A>;
a Simple RDF Parser and Compiler, written by Janne Saarela (W3C).
<H2>
  <A name="Appendix 3">Appendix 3: Generate Embedding on the Server side.</A>
</H2>
<P>
This appendix is for information purpose only.<BR>
As today most browsers are non-aware RDF browsers, we have to provide to
the user agent a comprehensive HTML page.
<H3>
  <B>A.3.1. &nbsp;Generate different type of HTML pages on the server</B>.
</H3>
<P>
A solution is to use a "transformation engine" hosted on the server (possibly
a servlet or a proxy).<BR>
This engine would read as input the HTML document &nbsp;and its linked RDF
document &nbsp;and transform these into an HTML document that includes either
OBJECT or APPLET or EMBED elements, though &nbsp;making it comprehensive
according to the client browser version and brands.
<P>
This engine could be dynamic (process on flight the proper HTML page compliant
to the client browser version) on client's request. These HTML generated
pages could then be cached on the server for future request. This engine
could also be a batch process to produce the alternative needed HTML page
to cover most browsers versions.<BR>
On client's HTTP request, the server SHOULD first discover the client browser
capabilities ( see <A HREF="#Appendix 4">Appendix 4</A>) and &nbsp;according
to these capabilities send the HTML page using the proper embedding.
<H3>
  <B>A.3.2. Benefits of generating HTML on the server :</B>
</H3>
<P>
This solution generation a final HTML page on the server from an HTML source
and RDF documents will:
<UL>
  <LI>
    allow to have standard HTML source pages hosted on the server. It allows
    authoring &nbsp;links with current authoring tools and no special extra
    knowledge.
  <LI>
    allow to have standard RDF files remaining on the server. It provides all
    the benefits of RDF stated in <A HREF="#Appendix 2">Appendix 2</A>.
  <LI>
    ease merchant's authoring and &nbsp;maintaining &nbsp;fee links as only the
    RDF document SHOULD be &nbsp;generated or modified. A light micropayment
    RDF authoring tool (based on a specific RDF Micropayment Schema) would facilitate
    &nbsp;editing these RDF files.
  <LI>
    allow future compatibility with RDF compliant Browsers without any changes
    on the HTML source document remaining on the server.
</UL>
<H2>
  <A name="Appendix 4">Appendix 4: Detecting the browser capabilities.</A>
</H2>
<P>
This appendix is for informational purposes only.<BR>
The Merchant server needs &nbsp;to detect the browser capabilities in order
to send &nbsp;to it &nbsp;the proper HLML page (with OBJECT or APPLET or
EMBED elements).
<P>
Browser capabilities &nbsp;depend on browser version and brand but also on
preferences set up by the user. The user can for instance disable JAVA, disable
Javascript, etc.
<P>
This detection can be done using Javascript.
<P>
<B>A.4.1 Detecting if the Browser is Javascript-enabled </B>
<P>
We can not write a JavaScriptEnabled() method in Javascript: a non-JavaScript
browser or a browser with Javascript disabled will not be able to process
the method call.<BR>
A simple solution is to use :
<PRE>&lt;SCRIPT LANGUAGE="JavaScript" TYPE="text/javascript"&gt; function1&lt;/SCRIPT&gt;
and &nbsp;&lt;NOSCRIPT&gt; function 2 &lt;/NOSCRIPT&gt;
</PRE>
<P>
One way of doing things is to redirect clients on test of enable or unable
to execute javascript :<BR>
A JavaScript-enabled browser executes the script &nbsp;(function 1) and
automatically redirect to a scriptable &nbsp;page "script.html"<BR>
A non-JavaScript browser follows the META element redirecting to another
non scriptable page "noscript.html"
<P>
<B>A.4.2 Detecting&nbsp;if the Browser is JAVA-enabled </B><BR>
<UL>
  <LI>
    Method for Navigator &gt; 3.0 :<BR>
    Syntax :javaEnabled() Parameters: None.<BR>
    Description: javaEnabled returns true if Java is enabled; otherwise, false.
</UL>
<UL>
  <LI>
    For Internet Explorer Only: <BR>
    Detect Java Virtual Machine version ... <BR>
    Syntax : document.jvm.Support()
</UL>
<P>
<B>A.4.3 Detecting if the Browser has the plugin installed</B><BR>
<UL>
  <LI>
    This works on Netscape &gt;&nbsp;3.0 and Opera Only:<BR>
    You can refer to the Plugin objects installed on the client by using an array.
    Each element of the plugins array is a Plugin object. <BR>
    Syntax : &nbsp;navigator.plugins[index]
</UL>
<P>
<B>A.4.4 Detecting with HTML elements</B><BR>
<UL>
  <LI>
    For &nbsp;EMBED elements: The NOEMBED tag specifies text to be displayed
    by browsers that cannot display content from plug-in programs. Browsers that
    can display plug-ins ignore all text in the NOEMBED tag.<BR>
  <LI>
    For OBJECT elements: If a Browser cannot determine or handle the type, it
    cannot embed the object, so it ignores the PARAM elements and parses the
    other HTML tags between &lt;OBJECT &gt; and &lt;/OBJECT&gt;.(a SCRIPT element
    for example)<BR>
  <LI>
    For &nbsp;APPLET elements: The content of the APPLET acts as alternate
    information for user agents that don't support this element or are currently
    configured not to support applets. One can insert a SCRIPT element in it.
    User agents ignores the content otherwise.
</UL>
<H2>
  <A name="Appendix 5">Appendix 5: Generate Encoding using Javascript on the
  client side</A>.
</H2>
<P>
This implementation generates the HTML page on the client side using Javascript
for example. After detection of the browser capabilities, &nbsp;if the browser
is Javascript-enabled, a script can generate the HTML elements and attributes
for each fee link.
<P>
This implementation allows the elimination of &nbsp;two HTTP round trips,
(one for browser capabilities detection and an other one to send the proper
HTML page)
<P>
Two possibilities have been overviewed :
<OL>
  <LI>
    Fee links parameters are passed in a SCRIPT element.
  <LI>
    Fee links parameters are passed in a META element as attributes or in RDF
    elements as RDF statements.
</OL>
<P>
<B>A5.1 Example of code generating HTML</B>
<P>
In this example all fee links parameters are passed in a SCRIPT element.
<PRE>&lt;HTML&gt;&lt;HEAD&gt;
&lt;TITLE&gt;Example of generated HTML&lt;/TITLE&gt;<BR>&lt;SCRIPT language="JavaScript"&gt;<BR>&lt;--
function markup(p1,p2,p3,p4,p5,p6,p7,p8,p9,p10)<BR>{<BR>Supports = navigator.javaEnabled();<BR>  if (Supports)<BR>  writeapplet(p1,p2,p3,p4,p5,p6,p7,p8,p9,p10);<BR>  else<BR>     if (navigator.appName.indexOf("Netscape")!=-1) <BR>     {<BR>       if (navigator.plugins["NPMINIPAY Dynamic Link Library"])<BR>       writeembed(p1,p2,p3,p4,p5,p6,p7,p8,p9,p10);<BR>       else<BR>       document.writeln("You don't have Micropayment plugin installed and
                          Java is not enabled in your browser")<BR>     } <BR>     else<BR>     alert("Please enable Java applets in  your browser to make micropayments")<BR>}

//This function formats HTML 4.0 for a Java Applet"
function writeobject(p1,p2,p3,p4,p5,p6,p7,p8,p9,p10)<BR>{
document.writeln (' &lt;OBJECT codetype="application/java <BR>classid="http://www.miamachina.org/applet/micropayment.class"&gt;')<BR>document.writeln (' &lt;PARAM NAME = "baseurl" VALUE="' + p1 +'valuetype="ref" ')<BR>document.writeln (' &lt;PARAM NAME = "merchantname" VALUE="' + p2 +'valuetype="data" ')<BR>document.writeln (' &lt;PARAM NAME = "buyid" VALUE="' + p3 +'valuetype="ref"')<BR>document.writeln (' &lt;PARAM NAME = "requesturl" VALUE="' + p5 +'valuetype="ref"')<BR>document.writeln (' &lt;PARAM NAME = "textlink" VALUE="' + p6 +'valuetype="data"')<BR>document.writeln (' &lt;PARAM NAME = "price" VALUE="' + p7 +'valuetype="data"')<BR>document.writeln (' &lt;PARAM NAME = "title" VALUE="' + p8 +'valuetype="data"')<BR>document.writeln (' &lt;PARAM NAME = "duration" VALUE="' + p9 +'valuetype="data"')<BR>document.writeln (' &lt;PARAM NAME = "expiration" VALUE="' + p10 +'valuetype="data" ')<BR>document.writeln ('&lt;/OBJECT&gt;')<BR>}
//This function formats HTML 3.2 for a Java Applet
function writeapplet(p1,p2,p3,p4,p5,p6,p7,p8,p9,p10)<BR>{
document.writeln (' &lt;APPLET codebase="http://www.miamachina.org/applet/"
code="micropayment.class" archive="myclasses.jar,myaudio.jar"&gt;')<BR>document.writeln (' &lt;PARAM NAME = "baseurl" VALUE="' + p1 +'valuetype="ref" ')<BR>document.writeln (' &lt;PARAM NAME = "merchantname" VALUE="' + p2 +'valuetype="data" ')<BR>document.writeln (' &lt;PARAM NAME = "buyid" VALUE="' + p3 +'valuetype="ref"')<BR>document.writeln (' &lt;PARAM NAME = "requesturl" VALUE="' + p5 +'valuetype="ref"')<BR>document.writeln (' &lt;PARAM NAME = "textlink" VALUE="' + p6 +'valuetype="data"')<BR>document.writeln (' &lt;PARAM NAME = "price" VALUE="' + p7 +'valuetype="data"')<BR>document.writeln (' &lt;PARAM NAME = "title" VALUE="' + p8 +'valuetype="data"')<BR>document.writeln (' &lt;PARAM NAME = "duration" VALUE="' + p9 +'valuetype="data"')<BR>document.writeln (' &lt;PARAM NAME = "expiration" VALUE="' + p10 +'valuetype="data" ')<BR>document.writeln (" &lt;/APPLET&gt;")<BR>}
//This function formats non standard HTML for a Plugin
function writeembed(p1,p2,p3,p4,p5,p6,p7,p8,p9,p10)<BR>{
document.writeln (' &lt;EMBED src="http://www.miamachina.org/MicropaymentPlugin.exe/"&gt;')<BR>document.writeln (' &lt;baseurl=+"p1"')<BR>document.writeln (' &lt;merchantname=+"p2"')<BR>document.writeln (' &lt;buyid=+"p3"')<BR>document.writeln (' &lt;requesturl=+"p5"')<BR>document.writeln (' &lt;textlink=+"p6"')<BR>document.writeln (' &lt;price=+"p7"')<BR>document.writeln (' &lt;title=+"p8"')<BR>document.writeln (' &lt;duration=+"p9"')<BR>document.writeln (' &lt;expiration=+"p10"')<BR>document.writeln (' &lt;/EMBED&gt; ')<BR>}<BR>&lt;/SCRIPT&gt;
&lt;/HEAD&gt;<BR>&lt;BODY&gt;
&lt;H2&gt;Generate [Embed] or [Applet] depending on Browser capabilities&lt;/H2&gt;

&lt;NOSCRIPT&gt;This page uses JavaScript. You SHOULD enable JavaScript &lt;/NOSCRIPT&gt;

&lt;SCRIPT language="JavaScript"&gt;
//Micropayment information needed for each fee link
markup("http://www.merchant.org/shop","ShopAndPay","catalog.html",
"elvis.html","Buy the biography of Elvis","+0.01USD",
"Biography of Elvis","60","1999-11-05T13:15:30Z");<BR>&lt;/SCRIPT&gt;
&lt;/BODY&gt;&lt;/HTML&gt;
</PRE>
<P>
<B>A5.2 Second example of code generating HTML</B>
<P>
In this second example all fee link parameters are passed in a META element.(same
kind of code would apply to parameters passed in an RDF element).
<P>
This needs to access the Document Object Model to extract META or RDF statements
in order to generate the proper HTML page with OBJECT or APPLET or EMBED
elements. <BR>
Netscape Browser Object &nbsp;Model in Navigator 4.x or previous does not
provide access to these elements. <BR>
Therefore this example works ONLY with Internet Explorer browser.
<P>
This code extracts attributes from META and RDF elements. To complete the
process, other code has to first detect the browser capabilities (as shown
in <A HREF="#Appendix 4">Appendix 4</A>), and generate an HTML page as above.
<BR>
<BR>
<B>a. Getting parameters from META elements</B>
<PRE>&lt;HTML&gt;&lt;HEAD&gt;
&lt;TITLE&gt;Example of Getting parameters from META elements&lt;/TITLE&gt;
&lt;META  name="baseurl" value="http://www.merchant.org/shop"&gt;
&lt;META  name="buyid" value="catalog.html" &gt;
&lt;META  name="requesturl" value="elvis.html"&gt;
&lt;META  name="textlink" value="Buy the biography of Elvis"&gt;
&lt;META  name="price" value="+0.01USD" &gt;
&lt;META  name="duration" value="60"&gt;
&lt;META  name="expiration" value="1999-11-05T13:15:30Z"&gt;
&lt;META  name="1.mpname" value="micropayment"&gt;
&lt;META  name="1.mpurl" value="http://www.foo.it/micropay"&gt;
&lt;META  name="1.specific" value="124rfdetg14ft58rdef21f4251"&gt;
&lt;META  name="1.mpbaseurl" value="http://www.merchant.it"&gt;
&lt;META  name="2.mpname" value="millipay"&gt;
&lt;META  name="2.mpurl" value="http://www.foo.it/millipay"&gt;
&lt;META  name="2.specific" value="475rdg546tfeww12wcft254hy4"&gt;
&lt;META  name="2.mpbaseurl" value="http://www.merchant.fr/"&gt;
&lt;/HEAD&gt;
&lt;BODY&gt;
&lt;SCRIPT language="JavaScript"&gt;
var coll = document.all.tags("META");
//Write the OBJECT element and it's parameters - for each fee link
document.writeln ('&lt;OBJECT codetype="application/java classid="http://www.miamachina.org/applet/micropayment.class" &gt;')
for (i = 0; i &lt; coll.length; i++)
{
document.writeln('&lt;PARAM NAME ="' + coll(i).name + '"' + ' VALUE="' + coll(i).value +'"&gt;');
}
document.writeln ('&lt;/OBJECT&gt;')
&lt;/SCRIPT&gt;
&lt;/BODY&gt;&lt;/HTML&gt;
</PRE>
<P>
<B>b. Getting parameters from RDF element</B><BR>
<PRE>&lt;HTML&gt;&lt;HEAD&gt;
&lt;TITLE&gt;Example  Getting parameters from RDF elements&lt;/TITLE&gt;
&lt;rdf:RDF&gt;
&lt;rdf:Description about="feelink-1" name="baseurl" value="http://www.merchant.org/shop"&gt;
....
&lt;/RDF:Description&gt;
&lt;/rdf:RDF&gt;&lt;/HEAD&gt;
&lt;BODY&gt;
&lt;SCRIPT language="JavaScript"&gt;
//Write the OBJECT element and it's parameters - for each fee link
document.writeln ('&lt;OBJECT codetype="application/java classid="http://www.miamachina.org/applet/micropayment.class" &gt;')
var coll = document.all.tags("RDF:Description");
for (i = 0; i &lt; coll.length; i++)
{
document.writeln('&lt;PARAM NAME ="' + coll(i).name + '"' + ' VALUE="' + coll(i).value +'"&gt;');
}
document.writeln ('&lt;/OBJECT&gt;')
&lt;/SCRIPT&gt;
&lt;/BODY&gt;&lt;/HTML&gt;

</PRE>
<H2>
  <A NAME="Appendix 6">Appendix 6: List of payment systems.</A>
</H2>
<P>
We need to &nbsp;guarantee unique naming for payment system names and avoid
collision.<BR>
For payment system names that are not registered in the following list, one
&nbsp;MUST provide:
<UL>
  <LI>
    a short code name. Names beginning with "x-" are officially unreservable,
    and thus may be used by any system with some local risk of name collision.
  <LI>
    a <A HREF="#URI">URI</A>.
</UL>
<P>
The short code name is the string that replaces $MP$ in URLs, but short code
names outside the following registry are meaningless. The
<A HREF="#URI">URI</A> &nbsp;identifies and determines wich wallets to activate,
not the short code name, allowing to prevent name collision. Therefore, a
payment system which is not listed in &nbsp;the following registry MUST provide
both the short name (prefixed by "x-") and the unique <A HREF="#URI">URI</A>.
<P>
Following is a small list of reserved short code names. We reserve the right
to extend it, or delegate control of it in the future, with a guarantee that
any changes or delegations will respect these rules and the names previously
reserved.
<P>
<TABLE BORDER CELLPADDING="5">
  <CAPTION >
    List of registered payment systems
  </CAPTION>
  <TR>
    <TH>Company</TH>
    <TH>Payment System</TH>
    <TH>Short Code Name</TH>
    <TH>URI</TH>
  </TR>
  <TR>
    <TD>Compaq</TD>
    <TD>MilliCent</TD>
    <TD>mcent</TD>
    <TD>http://www.millicent.com</TD>
  </TR>
  <TR>
    <TD>IBM</TD>
    <TD>IBM Micro payments</TD>
    <TD>mpay</TD>
    <TD>http://www.hrl.il.ibm.com/mpay/</TD>
  </TR>
  <TR>
    <TD>France Telecom</TD>
    <TD>France Telecom Micropayments</TD>
    <TD>mft</TD>
    <TD><I>to be specified</I></TD>
  </TR>
</TABLE>
<P>
<H2>
  <A NAME="Appendix 7">Appendix 7: Currency naming.</A>
</H2>
<P>
We need to guarantee unique naming for currency names and avoid collision.
<P>
For currency names that are not ISO 4217 codes registered,&nbsp;one MUST
provide:
<UL>
  <LI>
    a four to ten letters currency &nbsp;name beginning with "x-" to be used
    by any system with some risk of collision. In addition, one can also mention
    a meta-escape sequence; a new reserved prefix "z-" &nbsp;indicating any string
    starting with "z-" has "z-" removed from it before use. (e.g. &nbsp;z-x-u
    turns into x-u as a registered code, not into an x- extension string).
  <LI>
    a <A HREF="#URI">URI</A>.
</UL>
<P>
Example: a new currency for Air lines miles, could be named x-AM-zz (where
zz is the airline code) and identified by a <A HREF="#URI">URI</A>.
http://www.airline.com/zz
<H2>
  <A name="acknowledgments">Acknowledgments</A>
</H2>
<P>
The current and former members of the Micropayment Markup Working Group are:
<P>
Amir Herzberg, Chair (IBM); Anat Sarig, (IBM); Mark Manasse, Co-Chair (Compaq);
Thierry Michel, Editor (W3C); Jean Claudes Pailles (France Telecom); Phillipe
Michon (France Telecom) ; Aymeric de Solages&nbsp;(France Telecom).
<H2>
  <A name="References">References</A>
</H2>
<DL>
  <DT>
    <A name="CHARSETS">[<B>CHARSETS</B>]</A>
  <DD>
    Registered charset values. Download a list of registered charset values from
    <A HREF="ftp://ftp.isi.edu/in-notes/iana/assignments/character-sets">ftp://ftp.isi.edu/in-notes/iana/assignments/character-sets</A>.
  <DT>
    <A name="DATETIME">[<B>DATETIME</B>]</A>
  <DD>
    "Date and Time Formats", M. Wolf and C. Wicksteed, 15 September 1997. This
    W3C Note is available at:<BR>
    <A HREF="http://www.w3.org/TR/NOTE-datetime-970915">
    http://www.w3.org/TR/NOTE-datetime-970915</A>
  <DT>
    <A name="HTML32">[<B>HTML32</B>]</A>
  <DD>
    "HTML 3.2 Reference Specification", D. Raggett, 14 January 1997. This W3C
    Recommendation is available at:<BR>
    <A href="http://www.w3.org/TR/REC-html32"> http://www.w3.org/TR/REC-html32</A>.
  <DT>
    <A name="HTML40">[<B>HTML40</B>]</A>
  <DD>
    "HTML 4.0 Specification", D. Raggett, A. Le Hors, I. Jacobs, Revised 24 April
    1998. This W3C Recommendation is available at:<BR>
    <A href="http://www.w3.org/TR/1998/REC-html40-19980424">
    http://www.w3.org/TR/1998/REC-html40-19980424</A>.
  <DT>
    <A name="IANA">[<B>IANA</B>]</A>
  <DD>
    "Assigned Numbers", STD 2, RFC 1700, USC/ISI, J. Reynolds and J. Postel,
    October 1994. Available at:<BR>
    <A HREF="ftp://ftp.isi.edu/in-notes/rfc1700.txt">
    ftp://ftp.isi.edu/in-notes/rfc1700.txt</A>
  <DT>
    <A name="ISO639">[<B>ISO639</B>]</A>
  <DD>
    "Codes for the representation of names of languages", ISO 639:1988. For more
    information, consult http://www.iso.ch/cate/d4766.html. <BR>
    See also
    <A HREF="http://www.sil.org/sgml/iso639a.html">http://www.sil.org/sgml/iso639a.html</A>.
  <DT>
    <A name="ISO3166">[<B>ISO3166</B>]</A>
  <DD>
    "ISO3166: Codes for The Representation of Names of Countries." International
    Organization for Standardization.
  <DT>
    <A name="MIMETYPES">[<B>MIMETYPES</B>]</A>
  <DD>
    List of registered content types (MIME types). Download a list of registered
    content types from
    <A HREF="ftp://ftp.isi.edu/in-notes/iana/assignments/media-types">ftp://ftp.isi.edu/in-notes/iana/assignments/media-types</A>/.
  <DT>
    <A name="RDF">[<B>RDF</B>]</A>
  <DD>
    "Resource Description Framework (RDF) Model and Syntax Specification.", O.
    Lassila and R. Swick, 22 February 1999. This W3C Recommendation is available
    at:<BR>
    <A HREF="http://www.w3.org/TR/1999/REC-rdf-syntax-19990222">http://www.w3.org/TR/1999/REC-rdf-syntax-19990222</A>
  <DT>
    <A name="RFC1766">[<B>RFC1766</B>]</A>
  <DD>
    "Tags for the Identification of Languages", H. Alvestrand, March 1995.Available
    at
    <A HREF="http://www.ietf.org/rfc/rfc1766.txt">http://www.ietf.org/rfc/rfc1766.txt</A>.
  <DT>
    <A name="RFC2119">[<B>RFC2119</B>]</A>
  <DD>
    "Key words for use in RFCs to Indicate Requirement Levels", S. Bradner, March
    1997. Available at:<BR>
    <A href="ftp://ftp.isi.edu/in-notes/rfc2119.txt">
    ftp://ftp.isi.edu/in-notes/rfc2119.txt</A>
  <DT>
    <A name="SSL">[<B>SSL</B>]</A>
  <DD>
    Secure Sockets Layer (SSL V3.0) protocol, Alan O. Freier, Philip Karlton,
    Paul C. Kocher, November 18, 1996. This document is available at:<BR>
    <A HREF="http://home.netscape.com/eng/ssl3/draft302.txt">http://home.netscape.com/eng/ssl3/draft302.txt</A>
  <DT>
    <A name="URI">[<B>URI</B>]</A>
  <DD>
    "Uniform Resource Identifiers (URI): Generic Syntax", T. Berners-Lee, R.
    Fielding, L. Masinter, August 1998. Available at:<BR>
    <A href="ftp://ftp.isi.edu/in-notes/rfc2396.txt">
    http://ds.internic.net/rfc/rfc2396.txt</A>.
  <DT>
    <A name="XML">[<B>XML 1.0</B>]</A>
  <DD>
    "Extensible Markup Language (XML) 1.0 Specification", T. Bray, J. Paoli,
    C. M. Sperberg-McQueen, 10 February 1998. This W3C Recommendation is available
    at:<BR>
    <A href="http://www.w3.org/TR/1998/REC-xml-19980210">
    http://www.w3.org/TR/1998/REC-xml-19980210</A>
  <DT>
    <A NAME="XML-Name">[<B>XML-Name</B>]</A>
  <DD>
    "Namespaces in XML", T. Bray, D. Hollander, A. Layman, 14 January 1999. This
    W3C Recommendation is available at:<BR>
    <A href="http://www.w3.org/TR/1999/REC-xml-names-19990114">
    http://www.w3.org/TR/1999/REC-xml-names-19990114</A>
  <DT>
    <A NAME="XHTML">[<B>XHTML</B>]</A>
  <DD>
    "XHTML&#153; 1.0: The Extensible HyperText Markup Language: a Reformulation
    of HTML 4.0 in XML 1.0. A W3C Public Working Draft is available at:<BR>
    <A HREF="http://www.w3.org/TR/xhtml1">http://www.w3.org/TR/xhtml1</A>
  <DT>
</DL>
<P>
  <HR>
<ADDRESS>
  $Date: 1999/08/25 18:04:52 $
</ADDRESS>
</BODY></HTML>