Programmer-defined names
In a PL/I program, names are given to variables and program-control data. There are also built-in names, condition names, and generic names.
Any identifier can be used as a name. A name can have only one meaning in a program block; the same name cannot be used for both a file and a floating-point variable in the same block.
To improve readability, the break character (_) can be used in
a name, such as Gross_Pay.
These are some examples of names:
A Rate_of_pay
Record Loop_3
For additional requirements for programmer-defined external names, see INTERNAL and EXTERNAL attributes.
An asterisk (*) can be used as an identifier name in situations where a name is required but you do not otherwise refer to that identifier. For more information, see the example in ENTRY attribute.