In this article, we will discuss why terminological resources should be dynamic. This insight has an impact on the practical task of compiling and managing terminological resources. Dynamicity is an ambiguous term that can be used to express the ability to present terminological data in different ways, customized to specific user needs and it can also refer to terminological resources that are constantly updated in order to reflect the many conceptual and terminological changes in a domain. In the process of developing dynamic terminological resources, the ability to deal with different types of variation is of key importance. In this article, we will deal with both lexical variation (i.e. the fact that several terms may express a similar idea) and semantic variation (i.e. meaning differences between terms, synonyms and translation equivalents). We will focus on the PoCeHRMOM project in which a dynamic terminological resource of competency-based occupation profiles is developed for Flemish small and medium-sized enterprises. We will explain how different types of variation in occupation profiles are ‘managed’ and represented, using our own terminology management practices and tools.