Draconic Archivist
( Heroes of Horror, p. 122)[General]
In addition to your studies of the darkness, you have spent time studying dragons and constructs.
Prerequisite
Dark knowledge,
Benefit
You can use your dark knowledge ability on dragons and constructs. You use Knowledge (arcana) for dark knowledge checks regarding these two creature types.
Normal
Without this feat, a character with dark knowledge can use that class feature only on aberrations, elementals, magical beasts, outsiders, and undead.