'sign (and cert)' or just 'cert' on a master key with subkeus

[Dirk-Willem van Gulik]

I see a growing number of keys that have well managed & expired separate subkeys for Signing, Encryption and Authentication switch from ‘SC’ on the master key to just ‘C’ (all RSA, ignoring DSA).

Would anyone know if there is some documented best practice ?

Dw