When a reference work meets knowledge that a tradition confers rather than publishes, it has two options and only one of them is honest.
It can name the practice as closed and describe what surrounds it: the mechanics, the institution, the history, the state of the record, and the fact that the interpretive content exists and is held by initiates. Or it can reconstruct, assembling something plausible from whatever secondary material is circulating and presenting it in its own voice. The second option produces a fuller page and a less truthful one, and on a living religion it also puts words into other people's mouths.
These entries take the first option throughout, and the resulting narrowness is the accurate result rather than a shortfall.
Merinla, the fourteen-mouth throw, belongs to the upper tier of parent signs named by shell count. The atlas states its position in the sequence, its rarity relative to the lower signs and the naming convention it shares with its three neighbours, all of which can be checked against the published comparative literature.
What Merinla says when it falls is held by initiated diviners, and this entry does not supply a substitute for it.
Naming a practice closed is not a claim that it is hidden. Lucumi practice is public in most of what it does, and the scholarship on it is extensive. Closed here means conferred: acquired through initiation and training, and held by people who are answerable within a community for how they use it. The distinction matters, because the word secret invites the assumption that the material is simply out there to be found.