The Bank of England 10s note, commonly known as the 10 bob note or just the 10 bob was a banknote of the pound sterling. Ten shillings in pre-decimal money (written 10s or 10/-) was equivalent to half of one pound. The ten-shilling note was the smallest denomination note ever issued by the Bank of England. The 50P coin was the decimal equivalent of half a pound
A few other terms to be wary of when communicating across the pond: "Pissed" - American = angry, British = drunk, "Fanny" - American = ass, British = the other side of the female anatomy, "Rubber" - British = eraser, American = condom, "Durex" - American = sticky tape, British = condom.
A former boss of mine (USA) told the story of going to the UK and forgetting his "small carrying thing that goes around the waist." He went around to shops asking if they had a fanny pack. Apparently he got some strange looks. I always thought "Bob's your uncle" was a phrase originating with coins somehow, but I just looked it up and it's really (maybe?) from a PM named Robert in 1887 appointing his nephew Minister for Ireland.
As it turns out, I am visiting Liverpool on business next month and thought about your comment and had to look it up….. I suppose I don’t need to be meeting folks saying, “Hi I am Randy”…… I believe I need a nickname!