RPSL question

Dear Frank Bohnsack,

 Frank Bohnsack <Frank.Bohnsack at 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 at ripe.net>.

Regards,

A. M. R. Magee
______________
RIPE NCC