IBM Professional Series User Manual page 264

"share" a value by referring to it by a common name. When
requested, GLOBALV retrieves a variable(s) from the
group(s) and places it in the program stack for subsequent
use by the requesting EXEC.
GLOBAL V supports use of more than one group. This
allows for grouping distinct variables that are either related
or often used together, which facilitates both more efficient
retrieval and more selective use. The "global variable
group(s)," built by GLOBALV from a set of CMS
GLOBAL V type files on the user's A-disk and extensions,
exist throughout an IPL, unless explicitly purged or
re-initialized.
Retaining
When variables are defined or changed, the user decides
whether the variables or changes are to last:
1. For the current IPL only
2. Throughout an entire session (normally, from LOGON
to LOGOFF)
3. Permanently, i.e. across sessions
Variables defined for the current IPL only are retained in
storage. Those required longer than a single IPL are retained
in CMS files on the user's A-disk from where they are put in
storage. The CMS filenames are SESSION GLOBALV (for
values required throughout the session), and LASTING
GLOBALV (for values that are to last permanently). These
two files and a third A-disk file (INITIAL GLOBALV) are
the source from which the GLOBAL V command processor
creates and initializes the variable(s) in storage. The
INITIAL file is normally created by the user as an alternative
way of defining a large number of variables for an IPL.
The CMS GLOBAL V disk files may be of fixed or variable
format. Fixed format facilitates creation of files by users
(via editing).
It
accommodates variables whose names and
values do not exceed eight bytes each. The GLOBAL V
command processor uses variable format which allows for
varying length variable names and values. In addition,
Chapter 7. VM/PC Commands 7-91