The focus of this article is on external communication of product features intended to provide professional, commercial and private consumers with information on the characteristics of products and services. Mandatory approaches are distinguished from voluntary ones; the chapter is focused on the latter. Based on ISO standardization work, this chapter differentiates between qualitative, quantitative and self-declared voluntary approaches. Section 2 presents an overview of different concepts and approaches as tools applicable within Life Cycle Management. Section 3 deepens relevant approaches by describing some characteristic elements. Section 4 elaborates on a hierarchy, whereas the final Section 5 summarizes the outcomes and draws some conclusions.