A GLOBAL statement has the form
GLOBAL name,name,name...
and declares the variables or internal subprograms (external subprograms, by the nature of the system, already have the GLOBAL property) to be available externally.
A name clause can be replaced by name:character-constant to allow the external name to differ from that used in the program. That is,
GLOBAL X:'PROG25X'
allows other programs to refer to the variable called X in the current program by the name PROG25X.