User blog comment:Syst3ms/YAUD/@comment-30754445-20180810132619/@comment-25601061-20180811210714

ψM(x) is treated as an ordinal, yet it is not given an actual value. For example, ψM(M) could be the first inaccessible ordinal, yet it could also be the first recursively inaccessible ordinal or even just ψψ M(M) (εM+1). So we can't really say that UNOCF is an OCF, since the ordinals it collapses aren't actually defined.