Acknowledgements We would like to acknowledge several people which helped us with providing content to this document. In particular, would like to thank the members of the OntoWeb Content Standards SIG/Process Standards WG (see We would also like to thank all the people which read the document and provided constructive comments for improving its content. 1 Introduction The OntoWeb SIG on Content Standards focuses on one of the primary goals of OntoWeb: promoting the development of ontology-based metadata standards and content harmonization/interoperability across different standards for the creation, communication and sharing of such things as information, knowledge, products, capabilities, and process descriptions on the Web. The main goal of WP3 and the related SIG on Content Standards is to promote the role of well-founded ontologies in standards harmonization, in order to facilitate standards interoperability – or at least mutual understanding – across different communities operating in similar areas. As specified in the project workplan, this goal is to be achieved in collaboration with interested partners and will be focused on a limited number of selected standard clusters, suitably identified within the most relevant application areas on the basis of actual feasibility. The work to be done is organized into the following main phases: 1. Preliminary classification: A large set of potentially relevant content standards will be identified and classified on the basis of a preliminary classification scheme. Most relevant content standardization areas will be also identified. 2. Standard clusters selection: small clusters of standards with related content will be isolated, on the basis of actual interest from OntoWeb participants to ontology-based harmonization, comparison, or interoperability work. 3. Comparison and harmonization: For each cluster, ontology compatibility issues and harmonization requirements will be analyzed in a mixed top-down and bottom-up fashion. The more general issues will be discussed in a separate Working Group focused on foundational issues in ontology-based harmonization. 4. Comparison and evaluation framework.: this will be the final output of WP3 and the SIG on Content Standards. On the basis of the experience gained on selected clusters, a general comparison and evaluation framework for content standards will be developed, which shall be tested on a sample of standards selected from those analyzed in the first phase. This document describes the results of phase 1 above. It will be updated on a regular basis to include important missing standards and new emerging standards, as well as further suggestions concerning the classification …