5. Aeroplane Smoke Screens.
In addition to carrying small arms ammunition, this Squadron will be employed to drop phosphorus smoke bombs to obstruct the enemy's view. The areas to be screened and the time at which the screening in each case shall cease in order not to interfere with the advance of the Infantry will be shown on a map to be issued later.
Battle Instructions No. 17
ARTILLERY ARRANGEMENTS FOR THE LAST NIGHT BEFORE ZERO
1. S.O.S.
(i) Each line division will arrange for four field artillery brigades, or an equivalent number of guns, to fire on S.O.S. lines at any time up to zero minus fifteen minutes.
(ii) From zero minus fifteen minutes until zero hour S.O.S. arrangements will be inoperative.
2. Heavy Artillery.
In the event of the enemy opening a gas bombardment on the Villers-Bretonneux area, arrangements have been made for the co-operation of the Canadian Corps Heavy Artillery in an artillery counter-attack on enemy batteries. The Canadian Corps will deal with the enemy artillery about Wiencourt and Marcelcave. Fire will be opened, on application, direct between the two Corps Headquarters.
G.O.C., R.A., Australian Corps, will arrange details with G.O.C., R.A., Canadian Corps.
Battle Instructions No. 18
These are not reproduced. They refer only to Wireless Code Calls prescribed for all units.