Not totally limited to the British. Maybe some of the train ones, and in the U.S. "Coffee" can be substituted for 'Tea". I often feel remorse when I see the cup I forgot on the end table, with just enough of the contents evaporated to leave a slim, dark ring about 1/16 inch above the black, still surface which reflects your distorted, guilty face back at you accusingly...
I think it might have something to do with the colonies...