PSL rating is a type of rating scale used to rate the facial appearance of people. The acronym stands for a few different things.
P : Proportion - (
golden ratio,
dark triad etc)
S : Size - (size of facial features like
cheekbones, brow ridge, masseters etc)
L : Lineation - (contour lines of face, especially with hollow cheeks, sharp jawline etc)
PSL Rating is currently slang and not commonly used by surgeons or facial estheticians.