I donno the origin,but I DO know that the military (United Kingdom) doesnt have a problem with going regimental.....I recall a Pic of a kilted soldier lowering the flag in Hong Kong,and the back of his kilt blew up in the wind to reveal .....well lets just say ALL of Hong Kong knew what was under HIS kilt!

He didnt get in trouble for being regimental.....he got in trouble because his hose were uneven! so there you have it!!