Bjoern Hoehrmann wrote: 

People are typically not entirely agreed which and to which degree the
terms measure these. They are important and meaningful criteria however,
I would not say that about "work exactly the same" without considerable
qualification. In any case your definition does not account for "inter".

This is a classic QA discussion.  To some extent, what you care about depends on your /perspective/.  Terms like interoperability and compatibility are massively overloaded in the QA community.  Let me propose that we think about it, and therefore think about what problem we are trying to solve by writing standards in the first place, in a different way.

>From a content author perspective, what you really care about is what, in the old days, we called "portability".  In other words, the ability of your source (your XHTML 1.0 Strict document, for example) to operate correctly on a platform that claims to support your required standard.  If you only rely upon the parts of a standard that are mandatory, and possibly also gracefully fail when using parts that are optional that turn out to *not* be available, you are developing "portable" content.  Such content *must* operate seamlessly on any conforming user agent, *must* be correctly evaluated by any conforming search engine, etc.  That's content "portability".  As a content author, that's what I need.

>From the perspective of an implementor (user agent, search engine, whatever), what you care about is "conformance".  If I want to claim that I support a specific standard, I need to conform to the requirements specified by that standard.  When my implementation conforms to those requirements, I can be confident that my implementation will correctly process "portable" content.  And my user base can be equally confident. 

Think of a standard as a covenant.  It says "If you, the portable content developer, do things right, I, the content processor implementor, promise that it will work."

Regardless of the standard in question, this *has* to be our goal.  Anything else is just window dressing.

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Shane P. McCarron                          Phone: +1 763 786-8160 x120
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