Where are thre Release Notes for CA OPS/MVS located?  

Where are the Release Notes on CAOPS./MS v13.0 and v13.5 located?

CA OPS/MVS R13.0
CA OPS/MVS R13.5
z/OS

The Release Notes are found on the product documentation pages. 

For CA OPS/MVS Event Management and Automation (OPSMVS) R13.0 Release Notes use link
                             https://docops.ca.com/ca-opsmvs/13-0/en/release-notes/ 

The Release Notes for CA OPS/MVS R13.5 can be found at link 
                              https://docops.ca.com/ca-opsmvs/13-5/en/release-notes 

The complete R13.0 documentation is available at:         https://docops.ca.com/ca-opsmvs/13-0/en 
The complete R13.5 documentation is available at:         https://docops.ca.com/ca-opsmvs/13-5/en/ 

Likewise, you can access all Broadcom/CA product documentation by going to the following link and then typing in the product name into the Select A Product bar: https://docops.ca.com/home