Odd name resolution

[vr <debian-user@iotk.net>]

On my host I'm not sure why I'm able to ping "hostname.local" and get a
reply from my local IP. For example, the hosts name in question is
sager.mydomain.tld.

nslookup sager.mydomain.tld works as I'd expect.

nslookup sager.local returns NXDOMAIN.

I have my own DNS server and I don't have a .local zone defined anywhere
that I'm aware of or could find tucked away.

I don't have extra stuff in hosts:
cat /etc/hosts
127.0.0.1       localhost

I don't have a mailname file:
cat /etc/mailname
cat: /etc/mailname: No such file or directory

and my hostname output looks correct:
hostname -f
sager.mydomain.tld

Any ideas where hostname.local comes in?