... that this wholly admirable Tax should be enshrined in Law, to bite in 1973 (I think).
Oh, it bit alright, Danny. I left the RAF on 1st April 1973, having PVR'd. I had tried to get HMG to pay for my IRT course (at Kidlington), but the nice people at the Swindon Labour Exchange regretfully announced that the Training Opportunities Scheme had just been wound up, as they had surprisingly run out of money paying for much such training. Oh well, I suppose that was what the gratuity was for.
It turned out it was for more than that, as Kidlington regretfully announced that they were required to charge an extra 10% VAT on all their course fees, but hoped that their application to be registered as an Educational Establishment would soon enable them to refund me the impost. They hoped in vain, and the manic taxi meter that I imagined as sitting atop the instrument coaming of their Piper Twin Comanches spun at an even greater rate than originally envisaged. How I laughed at this splendid April jest!
The final word, as ever, from Wiki:-