Ok I followed your link but nowhere in that topic do they discuss logging only a part of a flight.
For example. You depart 10:00 and land 12:00. You fly as a passenger all the time except for 11 to 11:30 where you are flying as a student pilot.
How do you log this?
Do you write 10:00 - 12:00 in the logbook but on total time of flight only 0,5 ?
Or do you enter the time as 11-11:30 but with the departure and destination airports?
Do you enter blank departure and destination and only the time 11-11:30?
Or how do you log that?