I've just found a gap in my super-allknowing-entirelycomplete HTML reference.
It tells me how to code a whole bunch of characters, but I can't find anything that says precisely

Which characters do NOT need to be coded?

My recent shock was that "&047;" has to be coded (&047; or &slash;).
Thought this was a regular character.
A full colon doesn't seem to have to be coded, but since a semicolon is used as a code terminator, does it need to be coded?

Anybody have a list of the "Standard Character Set?"