Direct-to v. Proceed-to v. Own-Nav-to
What is the difference between the above? In the European airways context, they appear to be used interchangeably.
If the waypoint given is just one, I read it back as "direct to AAA, Nxxxx" in all cases, and fly a DCT AAA.
If the instruction is the much less common multi-waypoint one "own navigation AAA BBB CCC" then obviously I read it back as that, and start off with a DCT route to AAA.
I would guess that a DCT means DCT, Proceed To is just DCT in casual phraseology, whereas Own-Nav-To is a DCT but there isn't any traffic too close so it doesn't matter how exactly you get to the [first] waypoint.
I believe there may be an implied assumption of what one is supposed to do when the clearance is exhausted. If the waypoint given (or, in a multi-waypoint instruction, the last waypoint given) lies on your filed route, then you can revert to the filed route. Otherwise you are stuck in a limbo. In practice one would remind the ATCO before getting to the end of the clearance, of course. In a real lost-comms situation one would do the lost comms procedure (extra 7 mins on the last heading if in UK airspace IIRC, fly the clearance and then revert to flied route if elsewhere).
Any comments from airways sector ATCOs?