How can a login script determine if the session is remotely logged in?

[Roberto Michelassi]

I am currently a ksh user running on a Sun 3/60 with SunOS 4.0 and would like
to add a feature to my .profile or .kshrc file that would update the tool 
header of the window to display the message "RLOGIN" when I remotely log into
another machine. I know how to send the appropriate escape sequences to the
window to update the tool header, what I don't know is how to determine when
a script is being executed in a remotely logged in session.

I would greatly appreciate any suggestions you might have.