Dear Colleague, I'm writting a Perl RPSL parser module and have a understanding problem with part 2 "RPSL Names, Reserved Words, and Representation" page 5 of RFC 2622 ;-( "A value of an attribute may also be a list of one of these types. A list is represented by separating the list members by commas ",". For example, "AS1, AS2, AS3, AS4" is a list of AS numbers. Note that being list valued and being multiple valued are orthogonal. A multiple valued attribute has more than one value, each of which may or may not be a list. On the other hand a single valued attribute may have a list value." Ok, a multiple attribute value can be a single value or a 'comma list' of values. But the last sentence confused me - "a single valued attribute may have a list value" ? Means that "aut-num: AS123, AS456, ..." is a correct attribute of an aut-num object ?!?! Cheers Frank