Dear Frank Bohnsack, Frank Bohnsack <Frank.Bohnsack@de.uu.net> writes: * * 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 ?!?! No. The "aut-num" attribute can only appear _once_ in the "aut-num" object. In this sense, the "aut-num" attribute is 'single-valued'. But the value of the "aut-num" attribute itself cannot be a list. On the other hand, another attribute that can only appear once in an object may have a list as a value. However, the important idea here is that some attributes (especially the "members" attribute) take list values. In RIPE-181, this was not possible for any attribute. This and other issues will be discussed next Monday at the RIPE-38 RPSL Tutorial. If you have anymore questions, please contact <ripe-dbm@ripe.net>. Regards, A. M. R. Magee ______________ RIPE NCC