Legality of warnings

[clamb () ppws12 plk af mil (C Lamb)]

I recently saw an article on comp.security.unix concerning the 
need for posting warnings (i.e. of the don't log in w/o authorization
variety) at the login prompt.  I vaguely remember a way to do this
on AIX- some file which contains the login message displayed on
the console and when the system is serving telnet.

1) Does anyone remember the name of this file?

2) Is there an equivalent file in SunOS 4.1.3 and Solaris 2.3?

Thanks!