Well, not exactly. If people truly followed the standards, there would be no need for the meta charset element: the RFC clearly states that encoding should either be specified in the header or default to iso latin 1. I can't recall whether it makes provisions for media type specific default charsets, but either way, if you follow the HTTP standard, you should not specify content encoding in your text document (this of course does not apply to binary formats that migh encode text).

So, to be a bit pedantic about it, my argument is that you should follow the standards and ignore / work around the hacks used to make life easier for people that don't know / don't care about encoding.

Note that I do not mean that as condescending - at some point, a lot of designers were writing HTML manually, and I don't expect them to know about encoding, just the same as they hopefuly don't expect me to know about... design stuff I'm really terrible at.

Fair enough. Not condescending. I don't know much about HTML tbh.

However, if I were faced with your situation I would try to use whatever logic is used by firefox or chromium to work out encoding. After all designers are going to (should) test if things work on one/both of these right?