Nav Canada is changing Canadian ATC procedures to require aircraft to comply with published SID/Star altitude restrictions unless they are cancelled by ATC, starting February 9. According to NBAA, an aircraft that is assigned a SID/Star and then assigned a higher or lower altitude is still expected to comply with any published altitude restrictions on the SID/Star while climbing or descending to the new assigned altitude unless ATC specifically states “all SID/Star altitude restrictions cancelled.”