https://www.ibm.com/docs/en/ims/15.4.0?topic=parameters-armrst-parameter-procedures
IMS 15.4 - System definition - ARMRST= parameter for procedures
Use the ARMRST= parameter in procedures to specify whether (Y) or not (N) IMS registers with z/OS ARM and allows ARM to restart IMS in case of a failure. The...
imssystemdefinitionparameterprocedures