In article ,
"Maule Driver" wrote:

"Ron Rosenfeld"
They are probably saying "clearance on request" which means that they have
called ATC and requested your clearance. So yes, waiting for them to call
you back is proper.

Yep, what Ron said. It is non-obvious terminology for the pilot - maybe
controller obvious. But it's one of very many that you just get to know
after awhile.

It sure is non-obvious. I remember the first time I got that, during my
IFR training. The conversation went something like this:

"Clearance, Cessna xxxx, IFR to where-ever."

"Cessna xxxx, clearance on request."

[at this point, I figured the guy was telling me he'd give me my
clearance as soon as I requested it, as if it was another way of saying
"advise when ready to copy", so I said:]

"I'd like my clearance now."

You can imagine how the conversation went downhill from there :-)