This is standard for the closest degrees of kinship—father-in-law,daughter-in-law, &c.—but is frequently omitted in the case of more extended relations. As uncle and aunt are frequently used to refer to friends of the family. The terms may be used without specifying whether the person is a cognate (blood relative) or affine (related by marriage). A spouse of a cousin may not be called a relation at all or may be called a "cousin by marriage".
