When is a CNDJ not cancelled ?

Hi All,

Can anybody tell tell me , when working with PO's , when does the cndj field get populated ? , we have records in the F4311 that have a value in the cndj field but are not at status 980 999 , I thought that the cancelled date field would only get updated when a PO was cancelled , but this is not the case (with us anyway !) , can anyone tell me what the other times are please . Just for some more information on the recoreds in our system that have a cancelled date , the last