"CNAME and other data"
CNAMEs can't co-exist with other records (it defeats the purpose of defining a CNAME in the first place)
You cannot combine CNAME with anything else (except SIG when we are doing DNSSEC)
CNAMEs can't co-exist with other record types, so, by inference, you can't have a CNAME be the same as a zone name, since a zone has at least an SOA record (and, arguably, at least one NS record as well), and the CNAME can't co-exist with it. Just use an A record and be happy.
Indicates that you have a domain name in your zone data that owns both a CNAME record and a record of another type.