Soldiers of this regiment are distinguishable by the unique feature of the "flash", consisting of five black ribbons seven inches long on the back of the uniform jacket at neck level. This is a legacy of the days when it was normal for soldiers to wear pigtails. In 1808, this practice was discontinued, but the RWF decided to retain the ribbons with which the pigtail was tied, and was granted this special concession by the King.
The light infantry and grenadier companies of the Fusiliers saw bloody action at the Battle of Bunker Hill in the American Revolutionary War. The regiment saw particularly notable service during World War I, becoming forever associated with the terribly destructive action at Mametz Wood in 1916. During this war, several writers served with the regiment, including the poets, Siegfried Sassoon, Robert Graves and David Jones and Hedd Wyn. Their memoirs have resulted in the activities of this regiment being vividly recorded for posterity. Ford Madox Ford wrote movingly of the Welsh soldiers he commanded in his four-volume novel Parade's End.