The documentation for more recent releases is now found on our "docops" site:
From there enter in the "Select a product" box the version of CA Mainframe Application Tuner (MAT) that you desire.
For example, entering "main" will display the documentation releases of CA MAT that are available.
If you want to access CA MAT 11.0, you will go to the link:
This includes a section for messages and codes for CA MAT.