Baltimore poker is a variant that is more popularly called Low Chicago. It's a version of 7 Card Stud.
Instead of awarding the pot to the high hand, as in traditional stud, or splitting it between the high and best qualifying low, as in Stud/8, this game follows a different allocation for the low half of the pot. It goes to the person at showdown with the lowest spade in the hole (cannot have been dealt face-up).