Apart from the argument about syntax, what are (or will be) the rules about whether glue is required or not? That is: are in-domain nserver attributes required to specify at least one IP address? And are IP addresses for not-in-domain nserver attributes illegal? or ignored? In theory, at least, there is the always awkward question of "sibling glue", as in domain: 1.168.192.in-addr.arpa nserver: ns.2.168,192.in-addr.arpa [an-IP-address?] domain: 2.168.192.in-addr.arpa nserver: ns.1.168.192.in-addr.arpa [an-IP-address?] whose nserver attributes are individually not-in-domain. -- Chris Thompson University of Cambridge Computing Service, Email: cet1@ucs.cam.ac.uk New Museums Site, Cambridge CB2 3QH, Phone: +44 1223 334715 United Kingdom.