I was just editing an old question whose title ended with an exclamation point. I left the punctuation; I thought it was appropriate, since the question describes a surprising and counterintuitive situation. On clicking "Save edits", I was presented with this notice:
We've discussed the merits of the title filter before, and I'm not here to talk about that.
I just want to report, and ask for a fix to, the use of "word" to describe the punctuation mark.
The box should read:
Please do not use
<list of banned strings>in titles. See Writing Good Titles.
Where (hopefully this is obvious)
<list of banned strings> is replaced by all the bits of text the filter is blocking. This will provide a grammatically correct warning for anything that's in the filter list. (Thanks for the suggestion, Matt!)
Or, given that this restriction only applies to trailing punctuation marks (which is good, since
! is an operator in more than a few programming languages), perhaps some punctuation is worth a special case:
Please do not end your title with an exclamation point. See Writing Good Titles.
(Also, if you're going to capitalize the first word of the second sentence, why not the first? You've also got punctuation ending the first, but not the second, and the old "it's not a complete sentence" argument doesn't apply.)