I (Branch) - Intelligence section at Staff HQ.
I.D - Identity disc; bearing service number, unit, rank, name and religion. Initially only one disc of fibre or aluminium. Worn on string around neck. Post-1916, two fibre discs one green, one red. The green to be left on the body, the red to be collected as proof of death. Because of the poor durability of the issue discs some servicemen purchased their own in a heavier aluminium version.
IG - Inspector General of the Army.
Iron ration - Emergency ration carried in backpack. Usually included corned-beef (bully), tea (char) and army biscuits (hard tack).
