If Unicode maps the world's character sets, what standard, if any, maps the world's grammars? Is there place for date-/locale-specific standards?

[flautistnaturist]

And is there an etymological database intent on becoming detailed enough to pinpoint usage variants of living language down to sub-populations, sub-locales, etc?

[WindAtMyBack]

For English, no. There are "accepted" standards, which are really a matter of opinion.

My understanding is that with some languages there is an official standard for grammar. I think French is one of them.

I once had an English teacher in college. The first day of class he walked in and slammed his book on the desk to get everyone's attention. Then he loudly stated, "There are no rules to English".

Of course not everyone agrees with this. It's the difference between prescriptive linguists vs descriptive linguistics. One group thinks there is a fixed set of rules that should always be used. The other group thinks that usage is key, so that when large numbers of people use language in a certain way, then it is automatically "correct".

Dictionaries go by usage, and are fairly fast at updating how words are used. For example the Oxford dictionary recently removed the hyphens from thousands of words to reflect the modern trend of not using hyphens. Modern dictionaries use the Internet to scan billions of written words. They compile it and made changes on a regular basis.