Hierarchy
Decisions, formal power & structures
Knowing who actually makes decisions, and how, is one of the most useful things an organization can document.
Org charts describe reporting lines. They rarely describe how decisions actually get made: who has the authority to approve what, which things require consensus, where informal power sits, and who needs to be consulted even if they have no formal role in the decision.
In practice, the gap between the formal hierarchy and the informal one is where a lot of confusion and friction lives. New people get this wrong most often, but so do experienced people when the organization changes.
Documenting the hierarchy means capturing both layers: the formal structure and the informal reality. That includes decision rights, escalation paths, and the understanding of where things go when the formal process does not have an obvious answer.