Population microdata are typically organized into households, but household relationships are often ambiguous for persons outside the nuclear family. To facilitate comparative research on families and households, the Minnesota Population Center has developed consistent "pointer" variables identifying each person's mother, father and spouse for the International Integrated Public Use Microdata Series (IPUMS-International), a freely available database of 279 million person records from 44 countries. This paper documents the methodology used to identify the most likely parent-child and spouse pairings. We show that the IPUMS pointers agree with direct reports of family interrelationships more than 98% of the time, and highlight for researchers factors that affect the precision of these links. These new variables provide researchers with a common tool for studying family interrelationships, removing the possibility that differing results are an artifact of different linking procedures. A significant fraction of recent IPUMS data requests include the pointer variables, suggesting a growing body of population research will depend, at least in part, on the quality of these links.