Macrobending

All macroscopic deviations of the fibre’s axis from a straight line that cause signal attenuation.
Macrobends are bends that are large enough to be seen by the human eye. Macro bend loss refers to losses induced in bends around mandrels (or corners in installations), the bends necessary to fit fibres inside splice enclosures or patch panels.
Bend-insensitive fibres are intended to reduce macro-bending loss so cables could be run around corners better and fibres would not have as much loss when stuffed into small spaces.