Rare, and ambiguous: slash or comma.

"Virgule" (or rather, Latin "virgula", meaning "little rod" or, vividly enough, "little penis") was the name of a punctuation character shaped like a small slash and used in the Latin writing system much like a modern comma -- hence the ambiguity of this term in modern English.

Compare French "virgule" and Italian "virgola", meaning "comma" (not "slash"); Italian "doppia virgola" and "virgoletta", both meaning "double quote".