On a similar note, can anyone point me at a reference to settle a recent debate in my company. The question is this, once cleared something like "after departing BA A320 line up rwy 27 R via A1", can one taxi beyond the Cat 1 holding point/A1 (or another , earlier taxi clearance limit) to get close to the turn on for the runway in question-thereby reducing occupancy time to rolling (notwithstanding wake considerations) or must one wait until the said A320 has started his T/O. I've seen both techniques being used at LHR and would like to know the facts.