PICUS you can log for any successful flight test with an examinor.
That has been the UK's view in the past but it is not supported by Part-FCL. According to FCL.010, PICUS may be logged only by a 'co-pilot' which, in turn, is defined as "a pilot operating other than as pilot in command, on an aircraft for which more than one pilot is required...." Therefore, it would appear that PICUS may be logged only in a multi-crew environment.