Can I use something other than XHTML 1.1 in Opa?

I don't like MLstate's开发者_运维知识库 choice regarding XHTML 1.1 in Opa. Is there a way to use HTML 4.01 and HTML5?

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It's not the approved method, but it is possible. Take a look at module Resource. You can use it to export other kinds of resources.

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To the best of my knowledge: Opa was designed to work with well-formed XML mark-up, hence XHTML is a natural choice ("down-grading" it to HTML should be possible but I don't see a reason to do so -- what am I missing?). I believe it should be possible to use XHTML5, though, when the time is ripe.

If I may ask back: why would you rather use HTML 4.01?