Each person in a household may belong to only one family. A family includes :
- either a couple (married or not) and, if applicable, its children ;
- or a person without a spouse and his/her children (single parent family).
The child of the family is counted as such, regardless of his/her age. This may be the child of both parents, of one of the parents, an adopted child, or a child under the guardianship of one or other parent. No age limit is set to be a child of the family. A grandson or granddaughter is not considered to be a "child of the family".