What does or does not belong to a family—or whether a described family should be recognized at all—are proposed and determined by practicing taxonomists. There are no hard rules for describing or recognizing a family, or any taxa. Taxonomists often take different positions about descriptions of taxa, and there may be no broad consensus across the scientific community for some time. Some described taxa are accepted broadly and quickly, but others only rarely, if at all; the publishing of new data and opinion often enables adjustments and consensus over time.
The naming of families is codified by various international codes.