As a radar controller, can you clear an aircraft to a level previously occupied by another one in a way that you don't have 1000ft vertical separation between target Mode C indications as long as the following is fulfilled?
The question stems from the following paragraph in ICAO Doc 8.5.5.2.3:
"Aircraft vacating a level. An aircraft cleared to leave a level is considered to have commenced its manoeuvre and vacated the previously occupied level when the pressure-altitude-derived level information indicates a change of more than 90 m (300 ft) in the anticipated direction from its previously assigned level."