IBM SC34-5764-01 - Manual (Page 155)

The two environment names are automatically saved across internal and external subroutine and function
calls. See the CALL instruction (page “Purpose” on page 135) for more details.
The address setting is the currently selected environment name. You can retrieve the current address
setting by using the ADDRESS built-in function (see page 175).
ADDRESS
Chapter 13. Keyword Instructions 133