The instructions in job AXACTUPG used for the Active Upgrade process in CA Datacom/AD say:
//* 10. Use the same startup options as the CA Datacom/AD Version
//* 14.0 MUF. Copy 14.0 SYSIN(AXDATIN1) into the 15.0
//* CAI.CHLQ.CUSMAC(AXDATIN1). There are no changes required
//* to the startup options with 15.0.
Also, this same instruction is given in the Installing section of the CA Datacom/AD DocOps space, under the topic "Modify and execute the CAI.HLQ.ACT.INSTJCL upgrade JCL members" where it says:
4. Start the CA Datacom Version 15.0 candidate MUF.
. . .
Change the STEPLIB (CUSLIB and CAAXLOAD) to use the 15.0 libraries. Change the SYSIN to use the same startup options (AXDATIN1) input from the 14.0 MUF. EOJ the 14.0 MUF and start the 15.0 candidate MUF.