Agree with this. I've done plenty of travel in and out of DCA since moving to the area a decade ago. Old system you had to go through security for each terminal, so it was straightforward then and now to remember quickly which part of airport to get to. Particularly with terminal A having a separate entrance from B and C.

With the new security system in place the old system is moot, but having done travel knowing both guides (terminal and gate numbers) is still useful.