Photoluminescence
3.7. Photoluminescence: luminescence caused by the action of external light quanta, during which the frequencies of quanta and the spectrum of emitted light differ from the frequencies of quanta and the spectrum of exciting light
Source: "GOST R 12.4.026-2001. State Standard of the Russian Federation. Safety Standards System. Signal colors, safety signs, and signal markings. Purpose and application rules. General technical requirements and characteristics. Testing methods" (approved and introduced into force by Decree of the State Standard of Russia dated 19 September 2001 No. 387-ss) (redaction of 23 July 2009)