Define "user agent"

[jyasskin]

We use the term all over the place, but HTML never defines it. https://w3c.github.io/uievents/#user-agent has a decent definition.

[annevk]

What is wrong with the dictionary definition?

[jyasskin]

It's not in the dictionary: http://www.merriam-webster.com/dictionary/suggestions/user%20agent.
Also, a bunch of higher-level specs define it, and I'd like to centralize that.

[annevk]

Hmm, https://en.wikipedia.org/wiki/User_agent has it.

If we really want a list of central terms, we should also put things like ASCII whitespace, convert to ASCII uppercase, etc. in there. Not sure HTML is really the right place for all of that. I have often thought it would be useful to have, something similar to RFC 2119.

[domenic]

I think HTML is probably the best place we're going to get, at least for now. Especially for user agent, it seems like a good place, since so much of user agent behavior (navigation etc.) is defined in HTML.

We'll probably want to wait on solving this until #1012 lands since there'd be a lot of conflicts in adding the appropriate xrefs.

[annevk]

We should put this in Infra. That seems like the best place now we have it.

[domenic]

I still disagree, but not strongly. I think given that HTML defines so much about user agents, it belongs best in HTML.

[annevk]

I dunno, a user agent that performs navigation is not the user agent that Node.js is when implementing URL. So you need a more general form that works for independent implementations of URL, Encoding, etc.

[domenic]

Oh, that's a fair point. I guess let's draft a definition and see what things look like. Maybe what HTML would define is instead "interactive user agent" aka "web browser".

[tabatkins]

CSS's definition is basically just "an implementation of the standard".

[domenic]

FYI @jyasskin has a pull request out in whatwg/infra#269; thoughts welcome.