hi I read rfc2254 about LDAP v3 search filter. but I couldn't understand extensible filter BNF definition and that examples (cn:1.2.3.4.5:=Fred Flintstone) (sn:dn:2.4.6.8.10:=Barney Rubble) (o:dn:=Ace Industry) (:dn:2.4.6.8.10:=Dino) can anybody explain about this? thank you ...