- eyepatch removed (0) <-> eyepatch off (16)
- clothes removed (0) <-> clothes off (36)
- glasses removed (383) <-> clothes off (36)
- hat removed (1721) <-> hat off (0)
- helmet removed (0) <-> helmet off (90)
- shirt removed (3) <-> shirt off (0)
- shoes removed (107) <-> shoes off (16)
These tags are more-or-less the same thing:
- There is something wearable and someone in the same image, but the person is not wearing the thing.
There are a few small differences in descriptions, like glasses_removed saying that any pair of glasses that "are present in the pic but not worn" are fine, whereas hat_off says that someone was "supposedly wearing [the hat] a short while before the image". These nuances sound negligible, though.
Maybe they could be aliases one way or another, for consistency. Some of these already are.
The numbers between parentheses are the quantity of posts, according to the tag search. (http://danbooru.donmai.us/tag)
Updated by jxh2154