Besides the obvious „lign up“ (no other aircraft on the runway) or „lign up behind departing traffic“ (which implies to wait until the aircraft moves) clearances, I get the e.g „<callsign> behind the Airbus xxx, lign up“ or „ <callsign> lign up in sequence“ with the Airbus in question still ligning up in front of me or holding on the runway. With the clearance given, at what point may I cross the holding point line ( red stop bar lights are off)? Even before the aircraft on the runway moves if I judge there is sufficient space or strictly wait until the traffic ahead starts its take-off run? For example, in EBBR with crossing pair of runway in use (01 LDGs/ 07R DEPs) they usually have several aircraft ligned up on the same runway, using all the same holding point, to allow expeditious traffic departures. Any comments welcome!