Products and services categorization standards, such as eCl@ss, eOTD, RosettaNet Technical Dictionary (RNTD), or UNSPSC, play a major role for the automation of content integration tasks, because they provide a consensual vocabulary that can be used for the tagging of product-related data along the various stages of the product life cycle. Eventually, the quality and usefulness of a given categorization standard is determined by its content, especially the coverage of concepts in the respective application domain, its structure and semantic consistency, and the level of detail provided. This paper proposes metrics for the content quality of products and services categorization standards, and applies those metrics to four prominent examples. It can be shown that there are significant differences between eCl@ss, eOTD, RNTD, and UNSPSC, which should both influence the choice of a standard for a specific business purpose and the maintenance strategies for the standards themselves.