hostname

[john]

Hi all!
I am using dapper drake, and get this irritating warning about my hostname 
being invalid. I tried small.kubuntu, small.kubuntu.com, small_kubuntu, but 
hostnam just doesn't like it. I'd like to ask what are valid hostnames?
eg.
|root at mymachine:hostname small_kubuntu
|root at mymachine:hostname: the specified hostname is invalid

-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: not available
URL: <https://lists.ubuntu.com/archives/ubuntu-users/attachments/20051122/1c120ffc/attachment.sig>