In article ,
"Jim Macklin" wrote:

Maybe drinking cups should be sized like bras, the A cup
would be like those little cups they use at the dentist or
in your bathroom, the B cup would be a small cup of tea, the
C cup would be the standard 8 oz., and then the FFF would be
for beer at the ball game.

Makes sense. When I was in college, I used to frequent McSorley's
(http://en.wikipedia.org/wiki/McSorleys_Old_Ale_House). You couldn't order
one beer, they only came in pairs. Now I know the reason.