Some of the published indexes supply folio references to the act books and these references relate to the handwritten numbers in the volumes, and not to the stamped typographical numbers. If a folio number is not supplied for grants of administration made before 1719 it is necessary to ascertain the month of the grant from the index and then search through the relevant monthly section of the act book. (From 1660 to 1718 the administration act books (PROB 6/36-94) are organised into monthly sections and then subdivided into different seats. The basis of this organisation of business at this date is not known, and differs from the system formally introduced in 1719. For grants made after 1719 it is necessary to understand the seat system that was used by the Prerogative Court of Canterbury.
There is no act book extant for 1662, although contemporary calendars of administration acts for this year are available (PROB 12/39, PROB 13/96-97, PROB 15/72) (This act book was noted as wanting in General report to the king in council from the honourable Board of Commissioners on the Public Records Sessional Papers, House of Commons, 1837, 257).
For the years 1653 to 1654 a number of administration acts for these years have not survived.
The surviving administration act books for the years 1653 to 1654 (PROB 6/28-30) concerned have various different foliation systems owing to the fact that they are not original seventeenth century volumes, but consist of different gatherings bound together at a much later date. The different gatherings relate to different counties or other geographical areas.
After 1809 limited and special grants of administration ceased to be recorded in the administration act books in PROB 6. Instead they were recorded in a separate series of act books which now comprise the series PROB 7. The term entered at length alongside the name of an intestate in an administration act book for the years 1810 to 1858 (PROB 6/186-233) is a cross reference to the relevant act book in PROB 7
Most acts are recorded in summary form, the entries giving the date of the grant, the name and place of residence on the intestate, and the name of the administrator and his or her relationship to the intestate. Administration grants limited to a particular part of an intestate's estate are entered in full.
Except for the period 1651 to 1660 the act books are in Latin until 1733. From 1651 to 1660, and after 25 March 1733, the act books are in English, although certain technical phrases and abbreviations continued to be used in Latin.