Information always transmits a meaning. Human and machine communication relies on both the technological and the semantical exchange of information. The application of controlled vocabulary can support the semantical information exchange if certain interoperability criteria are fulfilled. The commentary paper will give an overview about semantics and semantical interoperability with a focus on controlled vocabulary. As a result, two exemplary semantic representation forms will be analysed. Further possible steps to enhance the semantics in metrological data and how to achieve semantic interoperability will be concluded from the commentary overview.