Biographical Database of Australia

Help : Categories of People

People mentioned in records of the Biographical DataBase of Australia are classified as primary or secondary persons. These categories determine whether all or part of the person’s records can be found via searching the main or the supplementary indexes.

One of the aims of BDA is to identify and link the records of each person, and to identify the first instance in Australia of a person, which may be as an arrival or as a birth.

Primary Persons

Primary persons are the main subject of a record. For example:

  • For a baptism, the child and both parents are the primary persons. 
  • For a marriage,  both the groom and bride are the primary persons.

There is only one primary person in a muster or census record (which may document several persons), in a convict indent or other convict administration record, or a shipping passenger record.


Secondary Persons

 Other people mentioned in a record are classed as secondary persons. For example:

  •  The record of a church service such as a baptism etc may include a few secondary persons acting as minister, witnesses, or guardians.
  • A muster record might include a note about the secondary person who is the spouse or parent of the primary person, or the householder, or a master of an assigned convict.


Main Index

The Main Index includes all primary persons, all persons for whom BDA has identified their first instance in Australia and all secondary persons who have more than one record in their Biographical Report.


Supplementary Index

The Supplementary Index contains records for people where only one biographical record has been identified for the person, where that person is a secondary person in that record.


Person Identity Numbers in BDA


Every person in BDA has a PersonID composed of an 11 digit composite number with a single letter prefix. It is BDA’s unique method to identify the linked personal records for a person and some aspects of their categorisation.

The single letter prefix has these meanings:

    • B means BDA has identified their first arrival or their birth in Australia.
    • L or T means BDA has identified more than one record for the person.
    • U means BDA has only identified a single record for the person as a primary person.
    • X means BDA has only identified a single record for the person as a secondary person.


Subscribers who send BDA staff information and/or corrections about a person and/or their records should include all of the following

    • the Person’s ID
    • the date of accessing BDA
    • the person’s name.


If BDA staff have identified further records for a person in an later release of the data then that Person’s ID number may change. The archival records of BDA will allow us to correlate altered PersonIDs across various vintages of the BDA data.