Great and cheap find, Erik!The white hat is indeed a maid's cap, and it is as unique as THE blue hat; it came only with the vintage set 3543 "aristocrats". The green hat you have there comes also with this set.http://playmodb.org/cgi-bin/showinv.pl?setnum=3543On the box' pic, the female klicky on top of the trunks is wearing the white cap, the gentleman in the middle wears the famous late 18th-century style blue hat.