This part of IEC 60793 establishes uniform requirements for measuring the macrobending loss of single-mode fibres (category B) at 1550 nm or 1625 nm, category A1 multimode fibres at 850 nm or 1300 nm, and category A3 and A4 multimode fibres at 650 nm, 850 nm or 1300 nm, thereby assisting in the inspection of fibres and cables for commercial purposes.