A couple of months before he was killed at Vimy Ridge, Private Ronald Mackinnon noted that he had to cut his letter to his father short because he heard “the joyful cry [of] ‘rum up’.” In the renches, everyone reacted when rum was issued. The rum ration was, in the words of Private E. Seaman of the 3rd Battalion, “the highlight of the day.” First Battalion infantryman Ralph Bell wrote that “When the days shorten, and the rain never ceases; when the sky is ever grey, the nights chill, and trenches thigh deep in mud and water; when the front is altogether a beastly place, in fact, we have one consolation. It comes in gallon jars, marked simply ‘S.R.D.’” That SRD was army issued Special Red Demerara rum.
Cook, Tim "“More a Medicine than a Beverage”: “Demon Rum” and the Canadian Trench Soldier of the First World War." Canadian Military History 9, 1 (2000)