What's the meaning of "Dj$w.$m" in /etc/mail/sendmail.cf

There is a config for /etc/mail/sendmail.cf:

# my official domain name
# ... define this only if sendmail cannot automatically determine your domain
#Dj$w.Foo.COM
Dj$w.$m

What's the meaning of "Dj$w.$m"?

Hi,
take a look at this link, it explains the "sendmail.cf" (Send Mail Configuration File)

Send Mail Configuration File

regards,
Alan Mehio
London, UK