In December 1918 the Class Z system was introduced by the army.  This system, which released huge numbers of men very quickly, created a reserve of soldiers who would be recalled quickly to the army if the armistice was to break down.

Many of the men who were discharged to the Class Z reserve had claims to pensions for disability - presumably an assessment was made that this disability would not prevent the man being useful to the army again in future.

The Class Z system lead to a new pension numbering format being used for these cases.

Class Z

The reference under the Class Z system was in the format of Z / Corps or Regiment / Sequential Number of claim from Corps or Regiment / Surname Split.

For example,

Z/DLI/1234

Z/MGC/1234/AtoK