Loon LLC Google Switzerland GmbH Google Switzerland GmbH Google Switzerland GmbH Google This document records a format whereby a network operator can publish a mapping of IP address prefixes to simplified geolocation information, colloquially termed a "geolocation feed". Interested parties can poll and parse these feeds to update or merge with other geolocation data sources and procedures. This format intentionally only allows specifying coarse-level location. Some technical organizations operating networks that move from one conference location to the next have already experimentally published small geolocation feeds. This document describes a currently deployed format. At least one consumer (Google) has incorporated these feeds into a geolocation data pipeline, and a significant number of ISPs are using it to inform them where their prefixes should be geolocated.