It is difficult for a browser to extract semantic information about commerce-related metadata described on a web page. Metadata such as cost, price, currency, purchase process, and the effective date of the currency are commonly expressed on the web, but are rarely marked up such that computers can understand the concepts (June, 2008).
The Commerce RDF vocabulary is used to mark up semantic information about metadata related to commerce. The easiest way to use the Commerce RDF Vocabulary is to use RDFa to embed the metadata into XHTML web pages. For more examples on how to use the vocabulary, see the Commerce RDFa examples on the RDFa wiki.
The Commerce RDF Vocabulary relies on aggregating functionality in previously defined vocabularies. Vocabulary term re-use is of primary importance. What follows are the vocabularies on which the Commerce RDF Vocabulary depends:
| Status | stable |
| Description | A unit of exchange consisting of a currency and an amount. |
| Subclass of | owl:Thing |
| Status | stable |
| Description | The type of currency used when specifying a transaction amount. |
| Datatype (pick one) |
|
| Status | stable |
| Description | The number of currency units involved in the transaction. |
| Datatype |
| Status | stable |
| Description | The effective date of the Price. |
| Datatype | xsd:date using ISO-8601 |
| Status | stable |
| Description | A link to a method of paying for a thing. |
| Datatype | URL using rel="commerce:payment" |
| Status | stable |
| Description | A reference from the current subject to a Price for the current subject. |
| Datatype | commerce:Price (containing both commerce:currency and commerce:amount) |
Commerce content consistently share several common fields. Where possible the Commerce RDF Vocabulary has been based on this minimal common subset.
Properties that are industry-specific are to be placed in separate vocabularies related to particular industries. For example, shipping-related commerce could be placed into a shipping-specific vocabulary, such as http://purl.org/commerce/shipping.
This vocabulary is the embodiment of a large group effort lead by Digital Bazaar, Inc. and pulls resources from the World Wide Web Consortium, the RDFa community and the Microformats community. It is a world-wide effort in semantic metadata standardization.
If you would like to extend this particular vocabulary, we ask that you engage the community in doing so. History has shown that if there is a wide-spread need for a vocabulary extension, it will be discussed, and agreed upon by the larger community before making it's way into the vocabulary. This process can take as little as a week. Work with us before forging out on your own, the knowledge of the masses are your ally.
This document is copyright 2008 Digital Bazaar, Inc. and is licensed under a Creative Commons Public Domain Dedication.
All ideas and patentable material outlined in the document are hereby dedicated to the public domain. It is our intent that all future additions, modifications and contributions will be dedicated to the public domain as well.
We have released our copyright and control of this vocabulary for the good of the community and the betterment of the world in the name of open standards.
We kindly ask that proper credit is given when using the vocabulary. A line like the following is sufficient:
The Commerce RDF Vocabulary is an initiative lead by Digital Bazaar, Inc. and collaborated on by a number of people from the Web at large, the World Wide Web Consortium, the RDFa community and the Microformats community.
Many thanks to the various individuals that did research and proposed ideas and discussion related to commerce vocabularies in general. Among the many participants are Rob Manson, Leif Arne Storset, Andy Mabbett, Martin McEvoy, Joe Osowski, Michael Johnson, Dave Longley, and David I. Lehn.
Many thanks as well to Mike Kaply, Ben Adida, Mark Birbeck, Ralph R. Swick, Shane McCarron, Michael Hausenblas, Steven Pemberton, and Mike Linksvayer for guidance with regards to RDFa.
Manu Sporny, Bitmunk - Digital Bazaar, Inc.
Manu Sporny, Andy Mabbett, David Longley, Michael Johnson, David I. Lehn.