Based on the review of the state of the art (Deliverable D1), suitable reasoning and meta-reasoning mechanisms associated to the processing of ontologies have to be identified. These mechanisms have to be classified according to their applicability in the various user activities in which ontologies are dealt with. This version of the ontology task handbook contains the revised proposal for ontology-based use cases and the associated reasoning and meta-reasoning services, to be used in the project. The set of ontology-based tasks underlying the identified use cases lays the basis for the whole project. The central role of these tasks makes it necessary to assess and validate their suitability in an early stage. For this purpose the selected tasks have been tested on small examples that are chosen so that the results of their application can easily be matched with the expected outcome. Based also on the inputs of the first industrial advisory team workshop (WP8), the set of ontology-based tasks have been finalised.