VMS Help CC, Messages, SWITCHLONG  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 Message        The signed or unsigned long expression "<expression>"
                is used in a switch statement.

 Description    A switch value has an integer type of signed or
                unsigned long int.  While Compaq C will allow this,
                some compilers will truncate the value to an int.

 User Action    Be aware of this if porting the code to another
                platform.