SPIC is only used in one form of training which is the zero to hero full time course in europe.
Its supervised pilot in command.
Basically these guys do that few hours (some come out with 160 total) that they needed to invent a way to get the required PIC time for CPL issue.
They don't have any licsense or ratings until they have completed the whole course. So they can't fly a twin solo as PIC. So they stick an instructor in the RHS and call it SPIC. The hours are actually dual with an instructor present in the cockpit and signing for the aircraft.