General relaxation of the rules on use of sub-domains

2008-05-13 - News - Chris Thompson

The restructuring of the database to allow free use of sub-domains, mooted in a previous article, has now been implemented.

As before, all names in the database have an associated domain whose value must be in a predefined table and is used to control user access. However this can now be any suffix part of the name following a dot (or it can be the whole name). If a CO has access to the domain, then they can register names such as (as previously) or, or even alone (although this last may be inadvisable). Such names can be used for "boxes" as registered and rescinded via the single_ops page, and also (to the rather limited extent that COs have delegated control over them) for vboxes and anames.

There are cases when one already registered domain name is a suffix of another, e.g. and Often these are in the same management zone and the longer name is present only to satisfy the previously enforced constraints. In these cases we shall phase out the now unnecessary domain. However, in a few cases they are in different management zones, with different sets of COs having access to them. It is possible for a CO with access only to to register a name such as, but its domain part will be taken as and not This is likely to cause confusion, and we will be relying on the good sense of COs to avoid such situations.

For CNAMEs, the mechanism using strip_components described in the previous article still exists at the moment, but it will be soon be replaced by a cname_ops web page in which the domain part is deduced automatically, as for the other database object types mentioned above, rather than having to be specified explicitly. (Now implemented, 2008-06-05.)

We advise that COs should not use sub-domains too profligately, and plan their naming schemes carefully. Any questions about the new facilities should be emailed to us.