From the perspective of open science, altmetrics are strongly associated with the impact assessment of scientific research. However, there are several other aspects to which the study of altmetrics can also contribute. Within OpenUP, we aim to provide an overview of how altmetrics have been used and described, in order to inform scholars and various stakeholders of how and when to use certain channels and how they can find relevant categories against which their work might be evaluated. In particular, our aim is to explore how altmetrics are connected to various channels of dissemination of scholarly output beyond publications, such as wikis, online sites for sharing code, or youtube channels. All these channels can reach specific audiences, but it is still unclear as to how they are relevant for the different scholarly communities. Through bibliometric analysis, expert interviews and validation exercises with stakeholder groups, we have developed a taxonomy of relevant categories by which various channels of dissemination can be assessed.