The protocol would require that the secure communications room in the White House that gets information from DOD, State, CIA, and similar “secure “ sources is going to be set up so that no information goes into or out of that area by any means. Such an area will only have information leave in approved formats carrier by and to people with the proper security clearances.
So yes, no Blackberry in the secure area. That is what Hillary with Mills and Huma had violated so profoundly.
I guess I should elaborate that secure areas do have information coming in and going out, but that happens over totally secure and isolated systems. SIPRnet is one of these systems — see:
https://en.wikipedia.org/wiki/SIPRNet