B1667/05 - (Issued for EGTT EGPX) AIR TRAFFIC STANDARDS DEPARTMENT HAVE BECOME AWARE THAT SOME ACFT ARE SQUAWKING UN-REQUESTED IDENT ON DEPARTURE FROM A NUMBER OF UK AIRPORTS IN AN ATTEMPT TO ASSIST CONTROLLERS IN IDENTIFICATION. THIS UN-REQUESTED IDENT DOES NOT COMPLY WITH THE REQUIREMENTS OF MATS PART 1 FOR IDENTIFICATION. THE CONTROLLER WILL THEREFORE HAVE TO REQUEST THE IDENT AGAIN. THIS NOTAM IS TO INFORM CREWS THAT THEY SHOULD ONLY SQUAWK IDENT WHEN IT IS REQUESTED BY ATC. 26 AUG 08:39 UNTIL 30 SEP 12:00 ESTIMATED