Some Slaves of Virginia The Cohabitation Registers of 27 February 1866 from the Lost Records Localities Digital Collection of the Library of Virginia,

Although the previous volumes in this series each contain an index, having all the indexes in one Master Index simplifies and defines which volume(s) you need to explore. Various spellings can be easily noted. Some of the difficulties in tracing a person from one county and owner to another may be removed.
These cohabitation records may help you put families together and aid in forming extended family members. The tables are comprised of two different types of information: A Register of Children of Colored Persons Whose Parents Had Ceased to Cohabit Which the Father Recognizes to be His and A Register of Colored Persons Cohabiting Together as Husband and Wife.
The Register of Children usually gives the child's name, age, place of birth, residence, and the last owner. Also included are the parent's names, ages, residences, and last owner.
The Cohabiting Records generally include the husband's and wife's names and ages, their residence, their last owner with his/her residence, and a list of their children and ages plus a date of the start of their cohabitation or the number of years together.
Although the information in each table is similar it may be arranged in different sequences. The place of birth is usually the county and the residence is usually the town. Ages are given and can aid in estimating a birth year. The same applies to estimating a death year. Some registers indicate children by a first wife. Names can be repeated more than once on a page with different owners, wives, and ages.