FOLIO - This column contains the folio number with the original census emnerator's book where the entry can be found.
A folio represents two pages where the individual was recorded on census night.
This reference is important if you want to look up a microfiche copy or obtain a photocopy.
You will also need the National Archives reference as well e.g. RG 12/xxxx (where xxxx depends on the town or village).