Is there any technical reason that a font should not have an apostrophe in its ID or filename?
What do you mean by "ID"?
Some of the name fields involved in a font do not allow apostrophes, such as the PostScript font name.
Also, what do you mean by apostrophe? The typewriter mark, or a true curly apostrophe?
Character U+0027—I don't want to use anything outside 7-bit ASCII in any identifier, because I'm not sure what kind of support it would have in older operating systems.
I'm aware the PS name has limitations; not even spaces are allowed. What I'm not sure about is whether there are any filesystems that would choke on apostrophe in a filename, or common APIs that wouldn't like it in another identifier.
AFAICT, it should be alright to specify for web use, as long as one escapes the apostrophe properly in CSS. In practice, some browsers may have problems. For instance, FF25 doesn't like the name inside a single-quoted string, even when escaped. (Should probably file that as a bug.) Putting it in a double-quoted string works fine w/o escapes.
Do you really need to use the apostrophe in your font names/ID? The English language uses the apostrophe for possessives but most other languages get along fine without it. An apostrophe would not be helpful for non-English language customers. Indeed, in some jurisdictions the governments have active programs to eradicate product names that use the apostrophe. I decided not to use it for "donshottype" or any of my fonts for international reasons as much as for the problems with font field naming.
I suspect that something, somewhere will choke on it in a menu name. But there's no way to be sure without extensive testing. Personally, I probably wouldn't push that envelope.
The name uses a term from a sci-fi pseudo-alien language. Of course, the way the writer made it look "alien" was to put apostrophes in odd places. It's probably not absolutely necessary to use it, but OTOH if it wouldn't cause problems, why not?
@donshottype:Indeed, in some jurisdictions the governments have active programs to eradicate product names that use the apostrophe.
Now that's odd. Of course, in Quebec, they have been eradicating signs in languages other than French, so Eaton's became Eaton... instead of, say, Chez Eaton.
@ChristTrekker:Of course, the way the writer made it look "alien" was to put apostrophes in odd places.
So they stand for glottal stops, and thus are an essential part of the name, just like the vowels and consonants.
… it should be alright to specify for web use, as long as one escapes the apostrophe properly in CSS.
@font-face just links a file resource to an arbitrary name, the web developer can choose. The internal name fields of the font are not relevant.