Eating of the Dead [908] & Advanced Sorcery [920]
To gain access to Advanced Sorcery [920], a noble must first study Artifact Construction [880] and Forge Auraculum [881]. Once an Auraculum has been forged, the magic school Advanced Sorcery [920] is automatically learned. This should be the only way a noble can gain access to this magic school.
The Necromancy skill Eating of the Dead [908], however, allowed a noble to consume the dead body of another noble and learn Advanced Sorcery this way.
This has now been fixed. Eating of the Dead [908] does a deliberate check for Advanced Sorcery [920] and ignores it. The sub-skills (Trance [921] and Teleport Items [922]) are not checked, so these should still be obtainable through the use of Eating of the Dead [908] (though only if Advanced Sorcery [920] is already known by the Necromancer).