Does wearing socks, stockings, etc mean a character is not in their underwear only? The wiki cheatsheet says underwear_only means no top or bottom wear and makes no explicit mention of socks. Personally I think it's fine, socks are basically a kind of underwear and I'm 100% with them in my search results for that tag.
And if they're not compatible the closest search terms I can think of to get underwear+socks would be "underwear legwear -topwear -bottomwear" which would run into a lot of problems with anything that has multiple characters/images, which seems like bad news for searchability.
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