[pbmserv] PGN versus SGF

["David J Bush" <twixt@cstone.net>]

| If you will be making game records available, this could be useful for 
| those who like to review their Go games.  I may add SGF for games like 
| Chess (where SGF is sometimes also called PNG),

PGN (not PNG) and SGF are different formats. PGN is by far the more widely
accepted format for Chess. Note that on the SGF website, several specific
game definitions are provided, but chess is not on that list.

http://www.red-bean.com/sgf/

Some major syntactical differences are:

* SGF does not number moves.

* Parentheses for variations are placed differently. For example, a PGN
  file might say: 4.Ba4 (4.Bxc6 dxc6) Nf6
  whereas SGF would look like this: (W[Ba4]; B[Nf6])(W[Bxc6]; B[dxc6])

See http://www.chessclub.com/help/pgn-spec for details.