TV Tabloid has a good and detailed explaination about this particular Howard Stern's tatoo.
Howard Stern pinky tat via kwout
The tattoo on Stern's right-hand pinky finger, is the Om symbol (which looks like 3) -- a sacred symbol for a number of religions including Hinduism and Buddhism -- which Stern said is pretty much meaningless to him.
The radio personality also has a letter B on the ring finger of his left hand - for his wife Beth Ostrosky. The couple got each other's initials instead of wearing wedding rings.
Of interest, check out Elle's Best Celebrity Inspirational Tattoos.
Tip! Inked Magazine shares 10 Tips For Getting a Tattoo.