[Users] AVPOP and openser DB key

I use avpops module. I use the user_preferences table (openser DB) as avp_table: modparam("avpops","avp_table","usr_preferences") But I have a question: In the description of avp_table is not required a key, in the default configuration of user_preferences table there is a key composed by user-domain-attribute. But with this key I can't use some different value for the same attribute: for example "fwdbusy". So I have delete this key, and the program is ok. Someone knows why in the user_preferences the key is composed those three values -- ======================================= Matteo Piazza, Junior Researcher CREATE-NET Via Solteri, 38 - 38100 Trento - Italy email: matteo.piazza(a)create-net.it Tel: +39-0461-408400ext:308 www.create-net.it =======================================