Charles Fourier‘s Hiérarchie du cocuage (1924)
“… let us first establish a hierarchy of cuckoldry and introduce into this serious debate the beacon of analytic method, which the philosophers regard as the path to truth. ”
“Among cuckolds, it is possible to distinguish nine degrees of cuckoldry, both among men and women, for women are cuckolded far more often than men; indeed if the husband has horns as tall as a stag’s antlers, the wife’s may be said to be as high as the branches of a tree.” —The theory of the four movements 
I stumbled upon this work via the excellent Anton Constandse Eros – de waan der zinnen (1977). The hierarchy of cuckoldry is part of a defense of free love.