According to
The Official Scrabble Players Dictionary,
OD is an
hypothetical force of
natural power. This word is also sometimes used as a
euphemism for
God.
O
1D
2 only scores a natural
three, but is
insanely useful if you like
sneaking in really high scoring
parallel plays.
Other favourites include: AA, HM, JO, MM, OE, PE, SH and XI.