It is best to use one compound variable for all local variables of
routines declared without the PROCEDURE keyword instruction.
The reason: In this case you need only the stem of this compound variable
as parameter for the keyword instruction DROP at the end of the routine
to delete all local variables. Likewise, you can use this one stem to initialize
your local variables all at once or to assign them all the same value at
some point in the program.
And, of course, if you're using unique stems for all procedures, your local
variables can't interfere with your global variables (or with the local
variables of other procedures).
Note: See Copy the Queue into a compound variable for a working example.