NOTIFY=&SYSUID
indicates that the user who submitted the job should be notified when it completes.
From the MVS JCL manual: NOTIFY:
In a non-APPC scheduling environment, requests that the system send a message to a userid when this background job completes.
&SYSUID
The system replaces &SYSUID with the user ID under whose authority the job will run, which is normally one of the following:
- The USER parameter from the JOB statement, if specified, or
- The user ID from which the job was submitted.