Online communities bring together people with varied access to and understanding of the work at hand, who must collaborate through documents of various kinds. We develop a framework articulating the characteristics of documents supporting collaborators with asymmetric access to knowledge versus those with symmetric knowledge. Drawing on theories about document genre, boundary objects and provenance, we hypothesize that documents supporting asymmetric groups are likely to articulate or prescribe their own 1) purpose, 2) context of use, 3) content and form and 4) provenance in greater detail than documents used by people with symmetric access to knowledge. We test these hypotheses through content analysis of documents and instructions from a variety of free/libre open source projects. We present findings consistent with the hypotheses developed as well as results extending beyond our theory derived assumptions. The study suggests new directions for research on communications in online communities, as well as advice for those supporting such communities.