Obscure Knowledge / Near-Impossible Difficulty

Obscure (hidden/unique) knowledge/information is a level of the scaled Knowledge Hierarchy. Knowledge may be ciphered/encrypted by various means.
This is knowledge almost never part of any recorded information, or recorded in such a way as to render it virtually unknown to all within a given setting. Typically such information is for the Game Master or the most complete and highest quality sources only. It has no set, specific parameters for its discoverability or scope – it is simply not available as part of any typical body of knowledge.

Example Scope of Knowledge: Although expressed as myth and metaphor, knowledge of the ancient “firsts” of the iVerse is not known or disseminated by any in any literal or meaningful way.