These are subject indexes to the Treasury Board papers and In-Letters in T 1. There are also two books noting superannuation precedents.
The Subject Registers were created by the Treasury Registry Room to enable them to trace Treasury Board Papers and In-Letters (series T 1) and are the main finding aid to T 1 from around 1852. The dates within each volume are not always as stated and may be a few years earlier or later for certain subjects.
For the papers to which these indexes relate see T 1
For further books noting superannuation precedents see T 211