Rational Developer for System z
PL/I for Windows, Version 8.0, Programming Guide

Suppress sign-on banner (/NOLOGO)

Syntax:/NOLOGO

This option suppresses the sign-on banner display when NMAKE is started. If you want to suppress nonfatal error messages and warnings as well, use the suppress messages (/C) option.

Rational Developer for System z
PL/I for Windows, Version 8.0, Programming Guide