A military issue kilt would have a label, similar to the one in this photo from another thread, with the broad arrow marking of the British Army:

http://www.xmarksthescot.com/forum/s...8&postcount=17

The Royal Stewart tartan was awarded to regiments by the Sovereign, and usually worn by pipers; for instance, the pipers of the Black Watch wear it, whilst the drummers wear Government Sett. In 1933, the 300th anniversary of the raising of the Royal Scots, the oldest regiment of the line, King George V awarded the regiment the tartan, which is also worn by their pipers. Just two examples.

Cheers,

Todd