Ifa is not a historical religion recovered from documents. It is practised now, in West Africa and across the diaspora, by people who would recognise themselves in any account of it and who have views about how they are described. That fact sets the terms of this entry more than any other consideration.
Three rules follow from it, and the atlas applies them across this whole type. Describe rather than instruct: a reference page can say what an oracle is and how it is structured, and should not read as a manual for using it. Name a closed practice as closed rather than reconstructing it: where knowledge is conferred by initiation, the appropriate response is to say so, not to assemble a substitute from whatever is circulating. And do not put the tradition's own voice in the atlas's mouth: statements about what a figure means belong to practitioners, and the atlas can report that they are made without making them.
The result is deliberately narrower than a page on, say, a tarot card. That narrowness is the accurate outcome for a living initiatory system rather than a shortfall in research.
Ose Meji, fifteenth of the sixteen principal figures, heads material within a conferred corpus. The atlas describes the corpus and the scholarship on it. The verses, the readings and the prescriptions are not set out here.