  Enterprise information systems have adopted Web-based foundations for
exchanges between heterogeneous programmes. These programs provide and consume
via Web APIs some resources identified by URIs, whose representations are
transmitted via HTTP. Furthermore HTTP remains at the heart of all Web
developments (Semantic Web, linked data, IoT...). Thus, situations where a
program must be able to reason about HTTP interactions (request-response) are
multiplying. This requires an explicit formal specification of a shared
conceptualization of those interactions. A proposal for an RDF vocabulary
exists, developed with a view to carrying out web application conformity tests
and record the tests outputs. This vocabulary has already been reused. In this
paper we propose to adapt and extend it for making it more reusable.
