Ross wrote:

All the times that I have used FF is just give a destination. Sometimes
ATC will come back and ask me to repeat the destination. I assume that
it is because I am not headed directly there. I tell them that I will be
flying such and such.

Or perhaps they do not know the airport identifier/location. I will
often use Colorado Springs as my destination instead of the smaller
Meadow Lake. You can't expect ATC to know every airport code in the
US.

Ron Lee