What phrase indicates that a pilot should remain outside Class D airspace when immediate provision cannot be provided due to traffic or workload?

The phrase that indicates a pilot should remain outside Class D airspace when immediate provision cannot be provided due to traffic or workload is "(call sign) Remain outside Delta airspace and standby." This instruction explicitly communicates to the pilot that they must avoid entering the Class D airspace and that they should hold their position while awaiting further instructions. This is crucial for maintaining safety and organizing traffic, especially in busy airspace where interactions need to be carefully controlled.

This clear directive helps prevent confusion, as it informs the pilot of the need to maintain their distance from the airspace, indicating that the air traffic controller is currently unable to accommodate them due to operational constraints. The phrasing ensures that the pilot understands the importance of staying outside the airspace boundaries until they receive further guidance.