"file info" standards, are there any?

I can't find anything from Adobe, or even IPTC on the exact intent of each field in the "file info". Does Adobe have official definitions of what should be put in these fields and what they mean?

Categories, Caption, Headline, Byline Title, Object Name, Original Transmission Reference -- just to name a few.

What I am seeking is an official statement from either Adobe or an established photo or press organization.

Thanks,
Rocky

How about the IPTC itself?

<http://www.iptc.org/metadata/>

Google is your friend

That page and the pdf it points to yield no information for me. It's odd because that's where it should be, if anywhere. But thanks for googling. I had actually already googled my fingers off before posting here. :(

Rocky