The Boy Scout manual for the UK lists alternative uniform items for UK scouts. For example, in Northern Ireland, the saffron kilt is an officialy recognized alternative to trousers.

http://histclo.hispeed.com/youth/you...o/scoutsco.htm

and

http://histclo.hispeed.com/youth/you...ir/scoutir.htm

...wherein you will find this bit of text:

***Some Irish Boy Scouts wear dark green or yellow saffron kilts for special outings like camping or in dancing comprtitions and of course Jamborees. ****

Finally, let's get to the meat of it.

http://www.netpages.free-online.co.uk/bbs/bbsbgs.htm

you will find this section.....

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11. KILTS.
11.1 Other than Ladies, Pre-Juniors, and Juniors (including Wolf Cubs) the following may wear the kilt with a plain leather sporran;
(a) Any Scout Officer holding any rank in the movement in Scotland, or Ireland.
(b) Any Scout Officer of Scottish or Irish descent (at least one Grand Parent of Scottish, or Irish Blood).
(c) Members of any Troop/Group in Scotland or Ireland, provided all wear the Kilt.
(d) Members of any Troop/Group where all the members are of Scottish or Irish descent (at least one Grand Parent of Scottish, or Irish Blood) and provided all wear the Kilt.
11.2 Those entitled to wear the Kilt may also wear, as an alternative headgear, a Khaki Bonnet. Similarly Rover Scouts may wear a navy blue balmoral.

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I'm sure that James and others could tell us about Boy Scout groups who have worn the kilt, and probably have memories of doing so themselves, when they were lads.