Hi Eddy,
You are correct, but they only use four colours, so why have I had two green ones and never had a blue one, I've retrained every three years?. It don't compute. They keep a record of when re-training is required and inform you anyway.
Marshals don't have to be IMC trained to marshal.

Have a search and send me a blue patch please.

I did have an experience when I was moved one year, it went something like this.....I arrived at a post manned by two ladies and a young man. After greetings he said "as you were here last you are on tea making duties" I didn't mind but then one of the ladies, pointing to the IMC patch on my tabard said to the fella, "He's IMC trained, he out ranks you, you're still the tea wallah" It was all taken in good humour and as I was asked to move yet again It didn't matter.
BTW at my regular post the owner serves us regularly with tea and biscuits..........Bostin.