When aircraft are to circle the airport, which type of traffic pattern info may be omitted?

When aircraft are instructed to circle the airport, the traffic pattern information that can typically be omitted is the direction of the traffic pattern, which is generally left unless specified otherwise. This is because a left traffic pattern is the standard configuration used at many airports unless traffic conditions dictate otherwise.

In instances where aircraft are circling, the essential information includes details about the approach—such as final approach and initial approach instructions—along with the specifics like distance from the airport for safety and proper spacing. The information about whether the pattern is left or right is often not needed as pilots operating under visual flight rules (VFR) will generally assume a left pattern unless they receive a specific instruction that indicates a different direction. Hence, omitting the left pattern designation does not compromise safety and allows for more efficient communication between air traffic control and pilots.