Specifies that IFAUSAGE is to return an indication of whether
the installation has requested SMF record 89. Register 15 and RETCODE,
if specified, will contain the return code indicating the status.
,LINKAGE=SVC
,LINKAGE=BRANCH
Specifies the type of linkage used in IFAUSAGE processing. LINKAGE=BRANCH
indicates branch entry. You may specify LINKAGE=BRANCH if you are
in supervisor state. LINKAGE=SVC indicates the linkage is by non-branch
entry, and is the default.
,RETCODE=return code
Specifies an optional fullword location into which IFAUSAGE stores
the return code. The return code is also in GPR 15.