On STAR, if after "...descent FL180 by ABC" we get "...descent FL150 by XYZ" it is clear to disregard first restriction. What happpens when second clearance is just "...descent FL150"?
If after "...descent FL180 by ABC" we get radar vector (from "present hdg to left/rigt 90*) are we to be given level abeam given point (hard if hdg change is big)?
For SID: In UK we have altitude restrictions on chart and initial level is not given in Clearance-pre-taxi (you take it from chart). In other places like Madrid, Rome... there are max altitudes on chart (at or bellow), and clearance altitude is higher. You can climb clearance level only passing these points. Does the departure ATC clearance above these altitudes before these points cancels SID restictions?