Is there any guideline about how to migrate codes after each major release? I am particularly interested in the Optical Physics module. I have not found anything in the documentation either the release notes.
As for the major changes in optical physics, especially scintillation, introduced in Geant4 10.7 and cemented in 11.0, I would suggest the section regarding scintillation in Book For Application Developers V10.7 . It gives a very detailed explanation of the new so-called “enhanced” way of modelling scintillation (which became the only way in 11.0 but was an option in 10.7) and compares all its parameters, specifications, methods, etc. with those of the pre 10.7 way. In my opinion, it is clearer than the 11.0 manual in explaining the differences and how to migrate.