Illič-Svityč's law
In linguistics, Illič-Svityč's law refers to two Proto-Slavic rules, named after Vladislav Illich-Svitych who first identified and explained them. Neuter "o"-stems. Proto-Slavic neuter "o"-stems with fixed accent on a non-acute root (accent paradigm b) become masculine, retaining the accent paradigm. Compare: This rule is important because it operated after the influx of Proto-Germanic/Gothic thematic neuters, which all became masculines in Proto-Slavic. Late Proto-Germanic (after the operation of Verner's law) had fixed accent on the first syllable. Compare: Masculine "o"-stems. Proto-Slavic masculine "o"-stems with fixed  accent on a non-acute root (accent paradigm b) become mobile-accent (accent paradigm c). This change is also termed "Holzer's metatony", after linguist Georg Holzer who described it. Older literature suggests that this was not a Common Slavic innovation, and that there are exceptions in some Croatian Čakavian dialects of Susak and Istria, which have retained the original accentuation. This has been recently disputed.