What does "minimum holding altitude" indicate?

The term "minimum holding altitude" refers specifically to the lowest altitude at which an aircraft can safely maintain a holding pattern. This altitude is designated to ensure safe separation from terrain, obstructions, and other air traffic, facilitating safe operations while the aircraft is in holding.

When an aircraft is instructed to enter a holding pattern, they must do so at or above this minimum altitude to ensure adequate vertical clearance and safety. This principle plays a critical role in air traffic management, particularly in busy airspace or when managing aircraft awaiting landing slots at airports.

In contrast, the highest altitude for holding patterns does not apply here, as there is generally no maximum holding altitude; it simply needs to be at or above the minimum. Optimal cruising altitudes are not relevant to holding and vary based on the flight segment, and standard altitudes in restricted airspace are governed by different regulations and considerations that do not encapsulate the essence of holding procedures.