Part of me would be puckering if I was cutting that service drop!.....But I believe it would refer to the buckling of the insulation on the inside of the bend that is too tight. No code section though...It exists, I just don't have it...
300.34 Conductor Bending Radius. The conductor shall
not be bent to a radius less than 8 times the overall
diameter for nonshielded conductors or 12 times the
overall diameter for shielded or lead-covered conductors
during or after installation. For multiconductor or
multiplexed single-conductor cables having individually
shielded conductors, the minimum bending radius is 12
times the diameter of the individually shielded conductors
or 7 times the overall diameter, whichever is greater.