Note 1 to entry: The unit nit (symbol: nt) is no longer in use.

Note 2 to entry: Other non-SI units of luminance:

• metric: lambert (symbol: L), ${\displaystyle 1\text{L}=\frac{10^4}{\pi }\text{cd}\cdot {\text{m}}^{-2}}$;
• non-metric: footlambert (symbol: fL), 1 fL = 3,426 cd·m⁻².

Note 3 to entry: This entry was numbered 845-01-53 in IEC 60050-845:1987.