The bulk modify feature of the Nominet Automaton can be a real time saver when you need to update a load of domains in one go.
For example, I just used it to add a tertiary name server to a load of domains under the FREETHOUGHT tag. To make sure that I only updated domains using the Freethought nameservers, I put a filter on the bulk update:
filter: ‘primary.freethought-dns.co.uk’ in nservers
update: nservers = [ ‘primary.freethought-dns.co.uk’, ‘secondary.freethought-dns.co.uk’, ‘tertiary.freethought-dns.co.uk’ ]
Nominet have some quite useful documentation along with several examples of the various update commands and filters available to control each of the different Automaton fields available on their web-site at http://www.nominet.org.uk/registrars/systems/auto/bulkmodify/