Regimental Trews.

I was wondering why is it only in the British Army's policy of allowing all ranks to wear tartan regimental trews dress(Scottish Units) and in the Canadian Army (Army Reserve Units-Highlanders & Scottish) I've only seen Officers wear them on occasion! The Cameron Highlanders of Ottawa is the only unit that I can base my own experiences on ie, seeing subalterns and senior officers wearing them for parade and garrison dress.

Why is it that NCO/NCM aren't issued them? Is this a cost factor!?

Is there any regimental unit regulations covering this subject??


Chris