What term is used to describe knowledge that exists in the system but cannot be reliably found or used by others?

Answer

Dark data

If an author uploads a report without correct metadata tagging, that publication effectively becomes 'dark data'—it resides in the system but is inaccessible for cross-domain searches.

What term is used to describe knowledge that exists in the system but cannot be reliably found or used by others?
knowledgeresearchportal