(A) Full cutoff. A fixture light distribution where no light intensity is emitted at or above a horizontal plane drawn through the bottom of the fixture and no more than 10% of the lamp’s light intensity is emitted at or above an angle ten degrees below that horizontal plane, at all lateral angles around the fixture.
(B) Cutoff. A fixture light distribution where no more than 2.5% of a lamp’s light intensity is emitted at or above a horizontal plane drawn through the bottom of the fixture and no more than 10% of the lamp’s light intensity is emitted at or above an angle ten degrees below that horizontal plane, at all lateral angles around the fixture.
(C) Semi-cutoff. A fixture light distribution where no more than 5% of a lamp’s light intensity is emitted at or above a horizontal plane drawn through the bottom of the fixture and no more than 20% of the lamp’s light intensity is emitted at or above an angle ten degrees below that horizontal plane, at all lateral angles around the fixture
(D) Noncutoff. A fixture light distribution where there is no light intensity limitation in the zone above the maximum distribution of light intensity.
(2003 Code, Chapter 28)