The formulation of the vocabulary of the types of grey literature in RDF (Resource Description Framework) provides an explicit conceptualization of the domain of grey literature. This type of modelling harnesses the expressive power of ontology languages for RDF data format and its flexible and extensible nature. Formalized in this way, the vocabulary serves as a means to describe grey literature resources in a structured, machine-readable manner. Adopting linked data publishing model affords the re-use and light-weight integration of the vocabulary with other vocabularies via links. The vocabulary built in this way can re-purpose existing vocabularies and re-purpose their concepts by putting them in a new context. This may lead to tighter integration of grey literature within the Web and make it easier to be discovered.