mipri, mipri cinri
mipri means "to keep something secret"; "to conceal". But what do we use for a non-agentive enigma? le se djuno bezi'o ('the thing known to no one') points to its ontological status.
Typically it is nalselju'o --Here is a case for the existence of zi'o.
nalselju'o implies "not known" but "could be known". le se djuno bezi'o says that no x1 (knower) place is to be considered in the meaning of this phrase.