Spell check uses a dictionary, if a word isn't in that dictionary the spell check will 'flag' it as mispelt. If you use those incorrect words regularly just add them to the personal dictionary which Firefox will consult before flagging them as misspelt.

What you are looking for would be more along the line of AI than a simple spell check.

Words with a number should be excluded from the spell check. Words that have a mixture of lower case and uppercase can cause a problem even if the lowercase version is known. You would have to add all upper/lowercase spelling variants to the personal dictionary to avoid flagging them.

Go to the Mozilla Add-ons Web Page {web link} (There’s a lot of good stuff here) and search for spelling / grammer checkers. .

Thanks for all of your suggestions. The real answer is that there really is no answer. I guess what I'm looking for is the option to ignore any 'word' that is ALL CAPS or includes any characters that aren't part of the regular alphabet. That shouldn't require anything like AI. It's really a bone simple feature that would require nothing more than bone simple programming.

@cor-el, thanks for pointing out that words with numbers are already ignored.

@FredMcD, thanks for recommending an add-on. When you mentioned it it seemed obvious; of course, why didn't I think of that? Interestingly enough, there are no advanced spell checkers! Well, that's not entirely true. There's one that spell checks everything on the web page, which isn't really what I want, and another that's a specialized medical and scientific spell checker. That doesn't really meet my needs either.

Firefox is open source. Maybe if I find the time I'll dig through the code and add the 25 lines needed to add the feature I want.

FredMcD said

Go to the Mozilla Add-ons Web Page {web link} (There’s a lot of good stuff here) and search for spelling / grammer checkers. .

themonkey said

@FredMcD, thanks for recommending an add-on. When you mentioned it it seemed obvious; of course, why didn't I think of that? Interestingly enough, there are no advanced spell checkers! Well, that's not entirely true. There's one that spell checks everything on the web page, which isn't really what I want, and another that's a specialized medical and scientific spell checker. That doesn't really meet my needs either.