"Snowbird"
But if you were going from, say, somewhere in Boston Center airspace
to Manassas, VA or to a smaller, more obscure airspace, chances are
excellent the Center computer won't have anything defining your route
and you'll be asked for the lat-longs of your destination or for a
nearby VOR. Sometimes you'll be asked for a VOR or airport defining
your route *inside the airspace of the center you're talking to*. It
ties up frequency and it's a hassle. Then there's the question of
what to do if you lose comms, or (more common) if ATC loses radar
coverage on you.

In my limited experience on the east coast, as long as the destination Lat
and Long are included (the Duats based stuff adds it automatically) the
direct route is generally accepted if I'm flying from something other than a
Class B or C airport with established procedures they like to follow. If
I'm flying to a B or C, I usually get cleared direct, then amended later if
again, they have some established procedures they like to follow - STARs or
undocumented