Acronym in chemistry: ROY for red, orange and yellow, designating a polymorph-model compound

The organic compound with the common name ROY is 5-methyl-2-[(2-nitrophenyl)amino]-3-thiophenecarbonitrile (C₁₂H₉N₃O₂S, see molecular structure above). The acronym ROY obviously does not abbreviate this structural name, but stands for the color adjectives red, orange and yellow associated with its multiple crystal forms or polymorphs [1]. Nine polymorphic systems are known for ROY, obtained by different crystallization/transformation procedures including crystallization from solution, melt and vapor phase.

Reference
[1] Joel Bernstein: Cultivating crystal forms. Chem. Comm. 2005, pp. 5007-5012. DOI: 10.1039/b509670g.