(Last updated 10 March 2006)

Attribute Value: "payment"

Description: rel="payment" indicates a URI where payment is accepted. It is meant as a
general way to facilitate acts of payment, and thus this specification makes
no assumptions on the type of payment or transaction protocol. Examples may
include a WWW page where donations are accepted or where goods and services
are available for purchase.

rel="payment" is not intended to initiate an automated transaction.

A link element with a rel="payment" attribute may exist at the feed/channel
level and/or the entry/item level. For example, a rel="payment" link at the
feed/channel level may point to a "tip jar"
URI, whereas an entry/item containing a book review may include a
rel="payment" link that points to the location where the book may be
purchased through an online retailer.

Display Characteristics: End-user software could support rel="payment" by displaying a "payment
button" along with the content. Alternatively, content aggregators may
display a payment hyperlink containing the text specified in a corresponding
title attribute within the <link> element, for example:

<link rel="payment" href="http://example.com/c.r.e.a.m"
title="give me the loot"/>

May display either a payment button or a hyperlink containing the text,
"give me the loot."

Security Considerations:

The link element is subject to tampering and observation, as is the linked
resource. For that reason, implementations should clearly signal the level
trust and privacy a linked resource provides. If present, digital
signatures provide authentication, message integrity, and non-repudiation
with proof of origin. Encryption provides data confidentiality.
Implementations should also consider the level of confidentiality and
message integrity provided by the transport used to reach the payment
resource.

(File created 10 March 2006)