Claim to Hospitality is a social, mundane advantage, described in Basic Set, pp. 41-42, and referenced in GURPS Low-Tech Companion 1: Philosophers and Kings™, p. 4, on gifting traditions between family bands; in GURPS Dungeon Fantasy 7: Clerics™, pp. 11-12, Dungeon Fantasy 8: Treasure Tables, p. 4, Dungeon Fantasy 9: Summoners, p. 18, and Dungeon Fantasy 11: Power-Ups, p. 16, all on hospitality for adventuring PCs, and in GURPS Mysteries, p. 107, on Claim to Hospitality as suitable for an investigator.