There’s a little bit going around at the moment about microformat validation; for example Norm Walsh on Validating microformats, Bill de hÓra thinks it matters Not a whit and the mailing list is going apeshit.
Is it true? Is validation not important? If, like Bill says, it’s important at publication time, then surely it is.
It’s important to note the stated intention of microformats to be
Designed for humans first and machines second. Whilst this might be true for the simple microformats like rel-tag rel-nofollow and so on, it’s certainly not true for the compound/complex microformats like hCard, for which there are already multiple tools for creation. I would go further and say that writing compound microformats by hand, as part of a normal HTML page is harder than writing a bare XML representation of your data.
Note that I do think that uF are a good idea, but the humans-firstness, in the context of uF like hCard is a joke and that without even the tiniest validation (of the uF, not the HTML) except to see if it works in multiple tools, it’s like actually wanting to smash your face repeatedly into a mirror.
I’ll accept a refutation when someone writes the equivalent of Mark Pilgrim’s Universal Feed Parser.