This format can...
read and write waypoints
This format is derived from the xcsv format, so it has all of the same options as that format.
The Garmin POI loader loads custom points of interest into certain models of Garmin GPS receivers. (As of this writing, only the models introduced in 2005 and later are supported. See Garmin's site for more info.) The garmin_poi format produces csv files that can be converted into POI files by Garmin's POI loader.
This format was mostly useful when POI Loader couldn't read GPX and we couldn't write GPI. See GPSBabel's GPI doc.