Ontologies can be practically applied in industry and governments to solve the current problem of lack of data integration including also the current inability for computers to interpret textual requirements as are present in standards and regulations. This can be realized through the definition and implementation of a formal ontological language that provides the concept definition models (dictionary-taxonomy) and language structure, and in which knowledge, requirements as well as product and process information can be expressed. This paper describes such a formal ontological language, called Gellish (a further development of ISO 10303-221 and ISO 15926), and its implementation in a universal database and message structure and it describes how that language is extended with a capability for the modeling of textual requirements. This enables usage of such requirements models to guide the design of facilities as well as for computer aided verification of designs and deliverables.