I just tested this and it seems to work fine? MBS-8621 is still an issue, but the apostrophe is not converted to ASCII. If I'm missing somewhere where this still happens, please reopen

There is now a clear style guideline that indicates a preference for UNICODE punctuation over ASCII https://musicbrainz.org/doc/Style/Miscellaneous#Use_of_special_characters .  However, Guess Case is still undoing track listings that have followed this advice and put in Unicode quotes rather than ASCII apostrophe's. Guess Case should leave such characters alone.

... and ellipsis too ("...")

The proposal changing the relevant part of misc guideline has passed, so we should do this now. Quote marks and dashes should be left alone too.

Please take this to the style mailinglist, as is there's not much I can do about this as a developer. I will close this ticket for now, feel free to re-open when there is a clear decision on mb-style about what Guess Case should and shouldn't do.

Also, I think the thread which added ellipsis to the list of taboo chars (http://thread.gmane.org/gmane.comp.audio.musicbrainz.user/8524) and specifically this post: http://article.gmane.org/gmane.comp.audio.musicbrainz.user/8816 summarize my feelings on this matter.

There's no blanket policy against using characters outside the basic ASCII set anyway, seems silly to single out these few characters.

Interesting. Perhaps that should be revisited, 5 years later and with improvements in Unicode support in OSes?

At the least, I don't think "Guess Case" is the place to be doing this kind of data validation. If we don't want to store/convert apostrophes, then it should simply be disallowed, not half-disallowed as it is now.

that's because of http://wiki.musicbrainz.org/Miscellaneous_Guideline