This paper discusses pragmatic ways of classifying knowledge maps to give an overview of their application formats and contexts. We show where and how the term knowledge map has been previously used and what criteria must be met in a sound and useful knowledge map classification. Various possible classification principles are presented. A table matches map formats to purposes and contents to serve as a selection framework in knowledge management processes. Examples of some of the main types of knowledge maps are presented to illustrate the varieties of knowledge mapping present in the classifications. The article concludes by discussing its limitations and future research questions.