The Battle of Minden, by by Dawn Waring (Source)
Wearing of Emblems with Uniform
Major T.J. Edwards, M.B.E., F.R.Hist.S., Some Military Customs and Survivals, The Army Quarterly, Volume XXXIX, October 1939 and January 1940
Wearing of Emblems with Uniform.— the custom of wearing emblems in various forms to commemorate important events is very ancient and is not entirely prohibited in the [British] Army, although "King's Regulations" prohibit the wearing of unauthorized ornaments and emblems with uniform. General authority is, however, given for all ranks when not on duty to wear their national emblem or flower on their respective Saint's day, i.e.—
- Rose on St. George's Day (23rd of April) for English personnel.
- Thistle on St. Andrew's Day (30th of November) for Scottish personnel.
- Leek on St. David's Day (1st March) for Welsh personnel.
- Shamrock on St. Patrick's Day (17th of March) for Irish personnel.
- All ranks are permitted to wear a poppy on Armistice Day (11th of November).
- Minden Day (1st of August). Of the more particular types of emblems worn perhaps the "Minden Roses" are the best known. … There are six "Minden" regiments.