[Home](./index.md) > [@keymanapp/kmc-model](./kmc-model.md) > [LexicalModelSource](./kmc-model.lexicalmodelsource.md) > [applyCasing](./kmc-model.lexicalmodelsource.applycasing.md) ## LexicalModelSource.applyCasing property Specifies the casing rules for a language. Should implement three casing forms: - 'lower' -- a fully-lowercased version of the text appropriate for the language's use of the writing system. - 'upper' -- a fully-uppercased version of the text - 'initial' -- a version preserving the input casing aside from the initial character, which is uppercased (like with proper nouns and sentence-initial words in English sentences.) This is only utilized if `languageUsesCasing` is defined and set to `true`. 14.0 **Signature:** ```typescript readonly applyCasing?: CasingFunction; ```