valid names on RRs

[spitz at us.ibm.com]

Is the following a legal name?

fred.barney    IN   A    1.1.1.1

Using a 4.9.3 server, the name fred.barney.xxx (xxx being my domain) is resolved
correctly, but I'm not sure if I'm violating any naming rules.  I would prefer
not to set up a barney.xxx domain.

In a quick look through the RFCs and the DNS and BIND book, I don't see anything
that tells me this in invalid.

Thanks,  Julie

SecureWay Communications Server for OS/390
(919)254-4421 (T/L 444), SPITZ @ IBMUSM25
Internet:  spitz at us.ibm.com