Folks,
Markerinbound make a very good point, he has touched on an area where US files a difference with ICAO Annex X, Vol. 2.
This, to an aircraft at FL350, the ATC instruction to " XYZ maintain 5000" is an unrestricted clearance, at pilots discretion as to TOD, to descend to 5000".
There are three phraseology differences, be aware.
Tootle pip!!