What are 'Removal Notches' and why are they critical for the maintenance of assemblies using spiral retaining rings?

Unlike stamped circlips, which have 'ears' with holes for pliers, spiral retaining rings are low-profile and have no protruding lugs. To facilitate removal, a small 'removal notch' (or slot) is provided on one end of the ring. This allows a technician to insert a screwdriver or dental-style pick under the end of the ring and pry it out of the groove. In aerospace applications, where 'FOD' (Foreign Object Debris) is a concern, the notch design must ensure that the ring end does not snap off during removal. Furthermore, the notch must be positioned so it doesn't create a stress riser in a high-load area of the ring.