The paper discusses the process of developing Semantic Annotations, a form of metadata for assigning conceptual entities to textual instances, in this case archaeological grey literature. The use of Information Extraction (IE), a Natural Language Processing (NLP) technique is central to the annotation process. The paper explores the use of Ontology Oriented Information Extraction (OOIE) methods for the definition of rich semantic-aware indices of archaeology documents. The annotation process follows a rule-based information extraction approach using GATE. In particular the report discusses a prototype development that adopts the core ontology, CIDOC CRM, together with an English Heritage archaeological extension, to inform and direct the information extraction effort. The prototype evaluation, supports the assumptions made, about the capability of the method to construct rich indices of grey literature documents empowered by Semantic Annotations.