The official naming used and found in official Air Ministry notices, the London Gazette and other publications is "R.A.F. Practice Camp Sutton Bridge". One example publication: FLIGHT, 24 May 1928, Air Ministry Announcements, Page 394: The Royal Air Force, Royal Air Force Intelligence, Appointments, I.W.C. Mackenzie to "R.A.F. Practice Camp, Sutton Bridge", 14.4.28 [1]
Publication: FLIGHT, 8 January 1932, Air Ministry Announcements, Page 43: The Royal Air Force, Royal Air Force Intelligence, Reorganisation of the Armament and Gunnery School, from 1 January 1932, R.A.F. practice camps will be known as armament training camps and numbered as follows...: No. 3 Armament Training Camp, Sutton Bridge [2]
Publication: FLIGHT, 27 May 1937, Page 552: Empire Air Day, Where and What to Watch Next Saturday, "Sutton Bridge.." [3]