From the
Solaris ftp manual:
-n
Do not attempt "auto-login" upon initial
connection.
If auto-login is not disabled, ftp checks
the .netrc file in the user's home directory for
an entry describing an account on the remote
machine.
Just another dot file that can be in people's
home directories. That is, if you don't have
read access, you can still check if the file exists.
It also saves time when using ftp, like .rhosts
saves time with rlogin or rsh or rcp.