Plain English Meaning
A small symbol on instrument charts that looks like the head of an arrow with feathers. It marks a spot where the pilot is required to report their position to ATC when not under radar contact.
Full Definition
A chart symbol used on IFR enroute charts to mark a compulsory reporting point at an intersection. The arrowhead has small lines (feathers) extending from it, distinguishing it from a non-compulsory reporting point, which is shown as an open (unfeathered) arrowhead.
Context Anchor
Seen on IFR charts when identifying intersections along routes or procedures.