Allow @PropertyKey annotation without specifying a specific bundle, where the property should be located. For example when internationalized properties are organized into multiple files and you want to allow a property from any of the files. Or when you use a library in your application that works with properties taken from the application classpath (there is no way how the library would know what property files would be used). This could be done by more ways. Including new annotation for that, or enable using special values in resourceBundle field such as "<project>" for any property file in the project, "<project+libraries>" for any resource bundle from project and libraries etc.