Say again slowly,
We were regularly operating up to 10,000ft and so leaning the mixture was taught from an early stage of training. Our type of flying was in the abnormal category according to your earlier classification but to be honest I've never heard it called that before.
Procedures weren't changed as such. Pilots were reminded of the importance of complying with the manufacturer's advice already in place. It was important that QFIs were fully informed and fully understood the importance of engine warming etc, as many military fliers of my era had been trained entirely on jet aircraft and only converted to piston engines later on in their careers.
