IBM SC34-5764-01 Manual page 187

The VALUE form of the SIGNAL instruction allows a branch to a label whose name is determined at the
time of execution. This can safely effect a multi-way CALL (or function call) to internal routines because
any DO loops, and so forth, in the calling routine are protected against termination by the call mechanism.
Example:
fred='PETE'
call multiway fred, 7
....
....
exit
Multiway: procedure
arg label .
signal value label
....
Pete: say arg(1) '!' arg(2) /* Displays: "PETE ! 7"
return
/* One word, uppercase
/* Can add checks for valid labels here */
/* Transfer control to wherever
*/
*/
*/
Chapter 13. Keyword Instructions
SIGNAL
165