dissymmetry of scattering

The ratio of two Rayleigh ratios for different angles of observation, i.e.
z θ 1 θ 2 = R θ 1 R θ 2
θ 1 < θ 2
The angles must be specified; in light scattering it is customary to let θ 2 = 180 ° − θ 1 and, most frequently, θ 1 = 45 ° and θ 2 = 135 °.
Source:
Purple Book, p. 67
See also:
PAC, 1983, 55, 931 (Definitions, terminology and symbols in colloid and surface chemistry. Part 1.14: Light scattering (Provisional)) on page 932