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Revision as of 22:46, 4 February 2008 by Tantek (talk | contribs) (added FAQs, XMDP GRDDL different, XMDP does not define typical namespaces - e.g. see overrides.)
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XMDP Frequently Asked Questions

This page is for documenting Q&A about XMDP. The contents here may be incorporated onto a gmpg.org page in the future, so please read the GMPG principles before contributing.

If you have a new question to ask, Please consider first asking your question on the microformats-discuss list.


  1. Why should I reference XMDP profiles in my documents?
    • In order to precisely define the classes and new rel values you are using as being defined by one or more specific microformats. With an XMDP validator, you will also be able to make sure that you are only using values that have been defined, and this may help catch problems with your content sooner rather than later.
  2. Must content marked up with microformats reference the proper XMDP profile(s)?
    • At this point we are saying that content marked up with microformats SHOULD reference the proper XMDP profile(s). This requirement may be changed to a MUST for microformat validity.
  3. How should a crawler or UA interpret an XMDP profile referenced in a document?
    • Very similar to DTDs. A crawler or UA may interpret an XMDP profile URL simply as an idenitifier for which it knows is a well-defined microformat vocabulary. It may also go read that profile URL, and parse it as XMDP, and thus mechanically know which class values are defined, which new rel/rev values have been introduced, and which <meta name> properties and values have been defined.
  4. Are XMDP and GRDDL very similar because they both use the profile attribute?
    • No. XMDP uses the profile attribute for defining terms, and GRDDL uses the profile attribute for defining how to transform.
  5. Does XMDP provide a namespace for terms?
    • Not quite. XMDP does provide a profile dictionary for terms, but not a namespace in the typical sense used for data (e.g. in XML) or programming language. One big difference is the way XMDP overrides work, as explained in http://gmpg.org/xmdp/description . Note that if two different profiles define the same term, only the first definition is used. Thus XMDP profiles are not "namespaces" in any data/programming functional way, as such namespaces make such multiple references exist simultaneously and distinctly by keeping them in their own silos.