- adjective only working when the characters are entered in either uppercase or lowercase letters
- adjective used to describe a command or operation that will only work when the characters are entered in a particular case
- Indicative of a program that distinguishes uppercase and lowercase characters. For instance, in a text search where the capitalization of words and/or letters is specified to pinpoint the desired results. Another example is seen on the Internet, where a uniform resource locator may require certain characters to be upper and/or lower case to access the correct Web address. This contrasts with case insensitive, where such distinctions are not made.