Yolngu religion is better documented than that of most Aboriginal nations, and the reason is not that less of it is restricted. It is that Yolngu leaders have repeatedly decided to present parts of it deliberately, in their own terms and for particular purposes. The bark petitions did this in 1963. The Yirrkala church panels, painted in the 1960s by senior men of both moieties for a mission church, set out clan narrative and design at monumental scale in a building where they could be seen.
The Saltwater bark paintings of the late 1990s were made to assert sea rights and were afterwards exhibited and published. Ronald and Catherine Berndt worked in Arnhem Land from the 1940s and produced a large body of published ethnography, and Yolngu knowledge holders have since collaborated with linguists, ethnomusicologists and astronomers on work published under joint authorship. Djulpan, the canoe of three brothers formed from the stars a Greek list calls Orion's belt, is in this atlas because of that kind of work.
None of it makes the whole of the tradition public. There is Yolngu knowledge restricted by clan, by moiety, by age and by initiation, and it is not in the literature; the absence of an account of something is not evidence that no account exists, only that none has been released. What the record contains is material Yolngu chose to put there, and for a living tradition that is the only kind of documentation this atlas treats as usable.