bhinnanimittaprayuktayos tvekasminnarthe vṛttiḥ sāmānādhikaraṇyam tac ca nīlotpalam ityādau vṛttāveva vyavasthāpyate
Co-reference is the application to one meaning of two [terms] prompted by different causes, and this is established only in compounds like "nīlotpala" etc.