SECRET. Sa/30

O.C. Battery.

1. In continuation of my Sa/27 of to-days date, if the 12th D.A. think that a counter attack on LONG TRENCH or an attack on HOOK TRENCH is imminent they will send the call: –
“ASSIST MARBLE.”

2. On receipt of this call the Brigade will put down the following Barrage: –
107. O.3.a.1.0. – O.3.a.0.2.
108. O.3.a.0.2. – O.2.b.8.5.
C/23. O.2.b.8.5. – O.2.b.65.70.
Rate of fire 2 rounds a gun a minute until orders are given to stop.

3. This will be a permanent possibility, and at any time on receipt of this call the above barrage will be put down.

4. ACKNOWLEDGE.

V.C. Ritchie Lt. R.F.A.