This chapter introduces annotation as a bifurcate practice and contemplates what it means to create and engage with different forms of annotation. Taking print media as a point of departure, the chapter aims towards media-specific understandings of annotation. The discussion contemplates how the annotating reader introduces a new voice to a source through the practice of derivative authorship. Annotation is characterised variously as a misdemeanour and invader of the text, a powerful tool for conversation and process of knowledge in-formation, and a means to disrupt linear reading experiences. As a tool for organising the world’s knowledge, the indexical and navigational properties of mark-up are also discussed.