Specifies that an element of the program is not a user-visible string which needs to be localized, or does not contain such strings. This annotation is intended to be used by localization tools for detecting strings which should not be reported as requiring localization.

• If a method parameter is annotated with NonNls, the strings passed as values of this parameter are not reported as requiring localization. Also, if the parameter of a property setter method is annotated with NonNls, values of that property in UI Designer forms are never highlighted as hard-coded strings.
• If a field is annotated with NonNls, all string literals found in the initializer of the field are not reported as requiring localization.
• If a method is called on a field, parameter or local variable annotated with NonNls, string literals passed as parameters to the method are not reported as requiring localization.
• If a field, parameter or local variable annotated with NonNls is passed as a parameter to the equals() method invoked on a string literal, the literal is not reported as requiring localization.
• If a field, parameter or local variable annotated with NonNls is found at the left side of an assignment expression, all string literals in the right side of the expression are not reported as requiring localization.
• If a method is annotated with NonNls, string literals returned from the method are not reported as requiring localization.
• If a class is annotated with NonNls, all string literals in the class and all its subclasses are not reported as requiring localization.
• If a package is annotated with NonNls, all string literals in the package and all its subpackages are not reported as requiring localization.

This annotation also could be used as a meta-annotation, to define derived annotations for convenience. E.g. the following annotation could be defined to annotate the strings that represent UUIDs, thus should not be localized:

@NonNls
@interface UUID {}

Note that using the derived annotation as meta-annotation is not supported. Meta-annotation works only one level deep.