Plain English Meaning

These are points marked on the chart where you only need to report your position if ATC asks you to. Otherwise, you fly past them without saying anything.

Full Definition

Geographical fixes shown on aeronautical charts as open (unfilled) triangles, at which a position report to ATC is not required unless specifically requested by the controller. They are typically used as navigation reference points along an airway or route.

Context Anchor

Seen on instrument charts and in non-radar procedures, especially when air traffic control is using pilot position reports to track progress.