Restrictions on &SYSUID Variable

Using the variable &SYSUID anywhere in your JCL degrades performance.
Using the variable &SYSUID on the JOB statement NOTIFY parameter might result in the failure of an Allocate request. If you code NOTIFY=&SYSUID and the user ID specified through the Allocate service is longer than seven characters, the Allocate request will fail. IBM® recommends that you avoid using the NOTIFY parameter in an APPC scheduling environment.
Using the &SYSUID variable on the DD statement SUBSYS parameter results in inconsistent symbolic substitution.
Note that, as described in the following section, you cannot use &SYSUID in a data set name in the TP profile JCL if the requestor's security specification is security_none.
Data sets on a JCLLIB statement should not use the &SYSUID variable.