The Field Representative's Manuals for 1985 and 1990 note that breastfeeding includes that given by a wet nurse or if the mother's milk was given to the child through a bottle. Further, the Manualdirects interviewers to footnote the situation (either "wet nurse," "bottle," or "natural"). In 1985, interviewers are further directed to, "...be sure to record the child's age when breastfeeding was completely stopped, not the length of time since it was stopped."

A similar variable, BREFSTOPRis available for 1981.