In this paper we explore the use of documents as interfaces to mathematical knowledge. We propose an augmented document model that facilitates the explication of a document’s notation context, i.e. the selection of appropriate presentations for all symbols in the document. By separating the notation context from the structure and content of a document, we aim at identifying the author’s selection of notation, i.e. his notation practices. This facilitates both, the identification of communities of practice (COP) that share specific notation preferences and, conversely, the adaptation of documents to the notation preferences of identified COPs, e.g. groups of readers and co-authors. Furthermore, explicating a document’s notation context allows for referencing and, particularly, reusing contexts, which reduces the author’s workload during the authoring process. 1