Hidden Lore of Hyboria
From GURPSworld Wiki
In addition to the standard Hidden Lore skills described in Basic (p. 200), there are two additional areas of lore specific to the Hyborian world.
Hidden Lore (Atlantean)
Knowledge of ancient Atlantis as well as that of other pre-cataclysm Thurian civilizations.
Hidden Lore (Hyborian)
Covers post-cataclysm lore, especially the history and lore of Acheron and the Khari, along with more recent lore of magic and sorcery.