[ineedasername]

They aren't a GPL, which is the true distinction. Otherwise, they are a language, and they are used to tell a computer what you want it to do. Seems like programming to me. If you're saying someone isn't a programmer when they only know HTML &/or CSS, it is more accurate to say they are not a GPL programmer.

That said, it's mostly about semantic conventions. And by convention, if you only work with HTML and CSS then calling yourself a programmer would give the wrong impression. "Developer" might be a more accurate designation, really "Front-End Developer". These days such a job with only HTML and CSS would be rare, but there was a time when those two things alone were just fine. Then again standards change: You probably wouldn't call someone an engineer if they only knew how to use tools from 500 years ago. It's just that things move much faster in computer tech.

[alpaca128]

HTML is a markup language, like the name already says. It's as much a programming language as XML, Markdown or JSON, so imho not at all.

But I'm not going to argue about this minor detail. Doesn't really make a difference.

[quantified]

Xml and json have no associated semantics, so they’re further away on the spectrum from programming languages.

Markdown has semantics in line with html (when interpreted by the right toolchain, of course), but far less than html.

It’s sort of like “what the line between being alive and being dead”, there’s a lot of grey and the trick is choosing your shade.