Lol - Ryan was pondering this also. So from the manual: "MATCH FULL will not allow one column of a multicolumn foreign key to be null unless all foreign key columns are null". So technically it doesn't make any difference on a non-multi column foreign key.

Other ref: http://www.postgresql.org/message-id/Pine.BSF.4.21.0109052151380.90362-100000@megazone23.bigpanda.com