The existence of a parent-child relationship is one of the foundations on which separate families and particular family composition categories are identified. It only refers to relationships between people usually resident in the same household. It includes relationships in which people actually report a parent-child relationship on the Census form (including being an adopted child or a foster child of an adult), as well as some designated relationships (i.e. for children aged less than 15 years who do not otherwise have a parent in the household, in which case a nominal parent/child relationship is established).
An individual may be (of household members) both a parent and a child at the same time (for example, a person could live with their father or mother and have a child of their own). If a child in a household is also identified as being a parent, then precedence is given to the person's role as a parent for family composition coding purposes.
See also Child, Family, Family Composition (FMCF), Parent.