Most of my tracks are shown with a green check mark.
But all my tracks with an apostrophe (straight, curly or whatever you name it) are shown with a difference in the title. Unfortunately I can’t see any difference between this two titles #1 and #2 in track number 8 of above album (“Don’t Let Me Lose This Dream”)
I don’t know how to do that, but I would recommend editing the release in MusicBrainz anyway, since U+2019 is the preferred character for an apostrophe.
And here is a scriptlet that someone once gave to me to change the apostrophe to a right single quotation mark for all items in a track list being edited. I keep it handy on the bookmark bar of my browser.
@Billy_Yank: THAT was it! Thank you very much for that hint!
This Option is enabled by default. After disabling it, I finally can compare the “real” values from my files with the one from MB.
Convert Unicode punctuation characters to ASCII: Converts Unicode punctuation characters in MusicBrainz data to ASCII for consistent use of punctuation in tags. For example, right single quotation marks (’) are converted to ASCII apostrophes ('), and horizontal ellipses (…) are converted to three full stops (.).