'For conspicuous gallantry and devotion to duty. At Hebuterne on the 16th July 1918 when the enemy counter attacked after our advance. Corpl. Duff organised his section into two parts, personally leading a bombing party of three men down the sap leading to the positions taken up by the enemy and by cooperating with the remainder of his section, who worked overland, drove the enemy from their post and held that part of the line until relieved. To Corpl Duff's bold leadership was due the success of his section. His extreme contempt of danger was an inspiration to his men and his fine work materially added not only in forcing the counter attacking troops back, but in still further extending the gains already secured.'
Source: London Gazette
Date: 21 October 1918