Definition of "User Agent (UA)"

[vkatsikaros]

The term User Agent (UA) is well defined in HTML 4.01 Specification as well as in Cascading Style Sheets Level 2 Revision 1 (CSS 2.1) Specification.

I am not sure if I can find a definition for User Agent (UA) in this specification. In case it is somehow "derived" I didn't spot it.

[zcorpan]

Is https://html.spec.whatwg.org/multipage/infrastructure.html#conformance-classes what you are looking for?

[vkatsikaros]

https://html.spec.whatwg.org/multipage/infrastructure.html#conformance-classes says

This specification describes the conformance criteria for user agents

but I can't find the definition of user agents.

To clarify I quote from HTML 4.01 Specification

HTML user agent

An HTML user agent is any device that interprets HTML documents. User agents include visual browsers (text-only and graphical), non-visual browsers (audio, Braille), search robots, proxies, etc.

A conforming user agent for HTML 4 is one that observes the mandatory conditions ("must") set forth in this specification, including the following points:

There, the text defines what an HTML user agent is as well as A conforming user agent for HTML

[domenic]

Dupe of #1021 it seems.