Products and services categorization standards (PSCS), like UNSPSC, eCl@ss, eOTD, or the RosettaNet Technical Dictionary (RNTD) form a valuable set of concepts from the product and services domain and reflect some degree of consensus. They are thus a promising foundation for the creation of products and services ontologies. Existing approaches for this task, however, do neither properly reflect the specific semantics of the respective categorization standards, nor do they sufficiently address the high versioning dynamics due to product innovation. This paper presents a comprehensive approach for the proper reuse of such standards in product ontologies