Question

where did the British preserve official documents?

Answer 1

British were of the opinion that to write about things and events is very important. Every instruction, plan, policy, decision, agreement, investigation had to be clearly written up. By doing so, one gets a chance to study things and events and discuss those.  

Answer 2

Answer:The official records of the British administration are an important source for the study of modern period.Tjey got every instruction,plan,policy,treaty,agreement,decision and investigation e.t.c

So the preserve their official documents in the record rooms that was built in archives or museums by the british