Hi Steven,

You've indicated that a "remain clear" stays in effect until ATC
issues a subsequent communication that permits or requires entry into
the class C airspace. This sounds reasonable. The real question is
knowing what communications permit or require entry into the class C
airspace and which ones do not so that when I'm in the air and hear a
communication I can know whether that communication suffices.

You wrote:
For the third or fourth time now, the controller would have to issue an
instruction that permitted or required entry into Class C airspace.
Examples are, "proceed on course", "fly heading XXX, vector for sequencing",
enter right base for runway XX", etc.

I'm not sure where you got this list.
Does "proceed on course" always permit entry, or does it depend upon
the relative positions of the airplane, class C airspace, and route of
flight? For example, if I'm headed away from the class C airspace
toward an intermediate waypoint and I hear the "proceed on course",
can I then go through the class C?

Thank-you!
Arden