I've recently noticed that restroom signs in Poland can be an inverted triangle and a circle for the men's room and the ladies' room, respectively. These signs are completely foreign to me and I was wondering what's the reason behind the choice of these particular symbols and if they are also common in other countries?
I don't didn't think there's anything specific to Poland here, fancy bars and the like have been experimenting with toilet signage for years. The Wikipedia article on gender symbols mentions that △/□ for male and circle ○ for female are used in genealogy, so this is likely cribbed from there, although (somewhat to my surprise!) the same article also notes that this is particularly common in Poland.
Random anecdote: around 15 years ago, I recall visiting a painfully hip bar in Bangkok that simplified things even further to a ◯ for women and a | for men, and jazzed things up a bit more with ice cubes in the urinal, producing visible steam in the tropical night. At least here the symbolism is fairly obvious.
