For most years from the mid seventeenth century there is a separate PROB 12 calendar for each year. Some eighteenth century and most nineteenth century calendars are in two volumes, with the first part of the alphabet in the first volume. In all the calendars, except PROB 12/30, 272-288, surnames of testators and intestates are sorted by initial letter only.
Those calendars that cover both wills and administrations have separate sequences for testators and intestates. In most seventeenth century and some eighteenth century calendars in PROB 12 the pages are divided in two, and testators appear on the left hand side and intestates generally on the right hand side. Occasionally information is given in the central margin between the two columns. This information relates to the names in the right hand column.
In the nineteenth century volumes the names of soldiers, seamen, and warrant and petty officers, including East India Company soldiers and sailors, and merchant seamen, are listed together.
The indexes to 1853 to 1858 (PROB 12/272-288) provide the same types of information as the other calendars in PROB 12 and are compiled on substantially the same principles. However, there is one sequence for the years 1853 to 1857, surnames are fully alphabetised, and there are not separate sections for soldiers and seamen.
Where there is an entry for an individual in the main part of the calendar accompanied by a reference to the soldiers' and seamens' part, or vice versa, it may be necessary to consult both parts. Some items of data may be omitted from one or other of the parts. In particular quire references to registered wills often do not appear in one of the two entries.
Compound surnames and surnames with prefixes are usually entered more than once under the initial letters of each of the elements in the name. Persons with more than one surname are generally entered under the initial letters of all their surnames.
The term otherwise, as for instance in Clark otherwise Williams, is variously abbreviated, most commonly to orwise, othw, and othwise. The term alias is often abbreviated to als.
The nobility are usually entered under the initial letters of their titles, and bishops and archbishops under the initial letters of their dioceses or provinces, and not under their surnames.
Data about occupation and status is not given for the majority of testators and intestates listed in PROB 12, although occupations are normally recorded for certain people such as clerics holding high office and members of the nobility and doctors and physicians.
In the Latin calendars stylised versions of the abbreviations dnus, dns (dominus meaning sir or lord), or ar (armiger meaning esquire) may appear in the left-hand margin preceding the testator's or intestate's surname.
Only senior military and naval officers are generally identified by rank in the calendars for pre-nineteenth century years. Other soldiers and naval seamen may be identified by the abbreviations serv or ser which stands for in servitio regis, or in servitio reginae (in the service of the crown).
The abbreviation serv preceding a ship's name indicates that the ship was a royal naval ship. Mt. S. stands for merchant ship, E.I.C.S. or E.I.S. for East India Company ship, E.I.M.S. for a merchant ship of the Company. Occasionally the term no ship is found. If this term is accompanied by the term Pts (or a similar abbreviation) in the place of residence position this indicates that the testator or intestate died overseas (foreign parts) but was not a seaman.
Some entries are annotated, generally in the left hand margin, with the terms poor or pauper (often abbreviated to paup) indicating that the deceased's executors or administrators were not charged fees on account of the paucity of the estates concerned.
PROB 12 calendars provide limited information about testators' and intestates' places of residence. In the case of the English and Welsh testators' and intestates' the county of residence is usually given, generally in abbreviated form, e.g. Ches for Cheshire (or county of Chester). Southampton (variously abbreviated to South, Southt, Southton) denotes the county of Hampshire and not just the town of Southampton.
Occasionally the PROB 12 calendars supply the names of towns or cities, other than county towns, and these are not intended to denote wider administrative units. The most common examples (with abbreviations in brackets) are Bath, Bristol (Brist.), Coventry (Cov.), Exeter (Exon.), Norwich (Norw.), and Salisbury (Saru.).
Scotland is referred to as North Britain (often abbreviated to N.B. or Nth. Britain).
The most common term given as a place of residence is an abbreviation for in partibus transmarinis, which was used for persons dying overseas and at sea. It is usually abbreviated to Pts but other forms such as Partibus, Parts, Ptibus, Pt were also used.
In the final column of the sections relating to wills in the PROB 12 calendars the number of the quire in which the will was registered in the will registers in PROB 11 usually appears.
All the quires of a single register are numbered in a single sequence regardless of the number of volumes in the register. In many Prerogative Court of Canterbury records and almost all finding aids to wills these quires are called by custom, though contrary to normal usage, folios, often abbreviated to fo: or fol. The numbers given in the PROB 12 calendars after the month of probate are the quire numbers. In the period for which searchers need to use PROB 12 calendars each calendar covers a single year and the quire number given is therefore the quire number in the will register for that year.
In addition to the original method of citing wills, references to registered wills (when cited in connection with earlier grants of probate) are sometimes made in the PROB 12 calendars by citing the month and year of probate. For example:
- Former grant August 1821;
- Prior facta Junij 1682.
In the case of references in this form it is necessary to consult the appropriate volume of PROB 12 (or printed or typescript index if one exists for the year in question) in order to find the quire number of the registered will. It should be remembered that before 1752 the beginning of the year was generally reckoned from 25 March and not from 1 January, and therefore in most cases a cross reference to an original grant of probate made between 1 January and 24 March before 1752, will have a year date in accordance with old style and not modern reckoning. Therefore in such a cross reference as, eg Former Grant Feb 1720 the year 1721 in modern reckoning is meant.
The terms vacat and vac are abbreviations for vacatur which means it is void. Cancelled entries in PROB 12 are marked, generally in the left-hand margin, with one of these terms. Cancelled entries were often replaced by other entries for the same testator or intestate and these can generally be found either near the cancelled entry or at the end of that particular letter section.
In order to locate a particular probate or administration act in the period 1719 to 1858 it is necessary to ascertain from the relevant printed index or PROB 12 calendar both the month in which the act was passed and the seat of the Court responsible. The seat responsible must be inferred from the place of residence given.