This chapter presents an ontology for customer complaint management, which has been developed in the CCFORM project. CCFORM is an EU funded project (IST-2001-38248) with the aim of studying the foundation of a central European customer complaint portal. The idea is that any consumer can register a complaint against any party about any problem, at one portal. This portal should: support 11 languages, be sensitive to cross-border business regulations, dynamic, and can be extended by companies. To manage this dynamicity and to control companies’ extensions, a customer complaint ontology (CContology) has to be built to underpin the CC portal. In other words, the complaint forms are generated based on the ontology. The CContology comprises classifications of complaint problems, complaint resolutions, complaining parties, complaint-recipients, ‘’best-practices’’, rules of complaint, etc. The main uses of this ontology are (1) to enable consistent implementation (and interoperation) of all software complaint management mechanisms based on a shared background vocabulary, which can be used by many stakeholders. (2) to play the role of a domain ontology that encompasses the core complaining elements and that can be extended by either individual or groups of firms; and (3) to generate CC-forms based on the ontological commitments and to enforce the validity (and/or integrity) of their population. At the end of this chapter, we outline our experience in applying the methodological principles (Double-Articulation and Modularization) and the tool (DogmaModeler) that we used in developing the CContology.