A different question from an out of towner. On initial contact with Hong Kong ATC when crossing the FIR boundary, I always give our squawk code. Why? Because everyone else does and I know that if I don't I will be asked for it anyways.
I had a management pilot tell me that I should not do this because it is not written down anywhere to do so. All arguments failed to convince.
Is this procedure actually written down or is it just done because we know it will reduce radio transmissions.