sitefilter takes a single argument which must be a quoted string. It is true if the argument string is a substring of the Site field of the game.
site "Open"An site filter may also be included as a CQL parameter, in addition to be used as an ordinary filter. For example,
cql (input i.pgn site "Freiburg") countsquares 4 10 qThe
sitefilter is used in the sample file gameinfo.cql . Examples