I guessed this before clicking, but its still interesting to know it exists. My next question is are they like invasion stripes on an aeroplane - i.e. they are

I guessed this before clicking, but its still interesting to know it exists. My next question is are they like invasion stripes on an aeroplane - i.e. they are changed before an operation so the enemy can't copy them - or are they coded depending on factors like rank or specific training, like the shapes on UK police cars?