Let's say there are altitude restrictions at 5000ft, 11000ft, 15000ft, 18000ft on a SID chart. While you were following the SID (under ICAO rules), the Departure tells you "Climb 12000ft, cancel altitude restriction." Does this instruction cancel all altitude restrictions on the chart or only restrictions below 12000ft?
'CANCEL LEVEL RESTRICTION(S)' cancels all the vertical restrictions above and below the new assigned level. From ICAO Doc 4444 16th edition (2016):
18.104.22.168 CLEARANCES ON A SID
CLIMB UNRESTRICTED TO (level) or CLIMB TO (level), CANCEL LEVEL AND SPEED RESTRICTION(S):
i) climb to the cleared level; published level restrictions are cancelled;
ii) follow the lateral profile of the SID; and
iii) published speed restrictions and ATC-issued speed control instructions are cancelled.
The same is true for clearances on a STAR (22.214.171.124).
The proper way to cancel specific restriction(s) and leave the rest is to specify the affected point(s).
CLIMB VIA SID TO (level), CANCEL LEVEL RESTRICTION(S) AT (point(s)):
A shortcut within the SID does not cancel the restrictions after the shortcut waypoint:
126.96.36.199.4 When a departing aircraft is cleared to proceed direct to a published waypoint on the SID, the speed and level restrictions associated with the bypassed waypoints are cancelled. All remaining published speed and level restrictions shall remain applicable.