[rdiff-backup-users] A small question about "users" on backups

[srusinsky]

On the man pages it is said that rdiff-backup keeps uid/gid informations
of files. 

I do suppose it does only keep numerical ID's, not the names ?

i.o. 
drwxr-xr-x   2 root  specialgroup      68 Mar 27 16:53 temp
would become
drwxr-xr-x   2 root  135       68 Mar 27 16:53 temp

supposing that specialgroup doesn't exist on the remote host.

Am I wrong ?

if this is the case is there any easy way to keep these names ( except
by creating a small DB )?

Thanks,

Stanislas.