DC ADIZ procedures?

In article ,
(Jay Masino) wrote:

Roy Smith wrote:
As far as I can figure out, all I need to do is call 1-800-WX-BRIEF
before I depart HPN and tell them I want to file an "ADIZ flight
plan". Then I get flight following and as long as I'm talking to
Potomic Approach I'm cool, right?

Same deal on the way out; I file with FSS, call Potomic Approach to
get a code before I take off, and that's it.

You've got it more or less, but you ABSOLUTELY need to get a discrete
squawk, and keep it all the way to the ground. You must NEVER squawk 1200
in the ADIZ, or you WILL be intercepted. You need to keep in contact with
Potomac Approach the entire time you're in the ADIZ. On the way out, do
NOT change back to 1200 until you are well clear (maybe 5 miles) of the
outer limits of the ADIZ, no matter what the controller tells you.

--- Jay

And what about closing the ADIZ flight plan? One thing I read stressed
that you MUST close your ADIZ flight plan, another thing said you don't
have to. Which is it?

Also, I assume if I go IFR all this is a moot point?