FCL010
"Dual instruction time" means flight time or instrument ground time during which a person is
receiving flight instruction from a properly authorised instructor.
So if you are receiving instruction it is Dual.
"Pilot-in-command under supervision" (PICUS) means a co-pilot performing, under the supervision of
the pilot-in-command, the duties and functions of a pilot-in-command.
The UK CAA has stated in an Alt AMC that this may also be used for SP Tests where the candidate passes.
SPIC is only used on Integrated courses for IR training.
And what about hours for the SEP revalidation (12+1 hours within last year). My understanding is that this is the only exception, since there you are performing a flight with the purpose of (re)obtaining a new licence
The requirement is a Dual flight or flights totalling 1 hour. In the case of a revalidation, you are not reobtaining anything, you are extending the validity of an existing rating.
Loging of flight time is delegated to National Authorities so you need to comply with the relevant National legislation.,