With the closing of gadgets.se, numerous questions were auto-merged into apple.se. Unfortunately, we're now getting some weird tag side-effects.
Many tags now show as duplicated. No, they're not just ones that look similar, they're actually listed twice with the same number. For instance, see accessories or address-book on this page.
Because of the duplicate weirdness, some questions have ended up with more than five tags. For instance, iOS keyboard settings change on their own has seven (5 actual + 2 dupes).
When I try to clean up the tags, things get even hairier. For instance, when I tried to remove the mobile-phone tag on Least expensive prepaid data roaming with an unlocked iPhone in the US, the question ended up with prepaid twice. Right now, it has four tags (3 actual + 1 dupe)—but when I try to add another, I get the message that the question already has five tags.