When do we need to update GENERIC_LIB_VERSION / KDE_NON_GENERIC_LIB_VERSION ?

[Albert Astals Cid]

One of the release team files says

When doing release, update:
 * cmake/modules/KDE4Defaults.cmake

set(GENERIC_LIB_VERSION "4.9.0")
set(KDE_NON_GENERIC_LIB_VERSION "5.9.0")

When does this need to happen?

For every release? For every .0 release? For every .0 release + for 
alpha/beta/rc?

Anyone knows?

Cheers,
  Albert