PA nonrestrictive/incidental relative clause; attaches to a PA number/numeral/digit with the ke'a referring to that PA number/numeral/digit.
It attaches to the last mentioned PA, which can be only a single digit within a number rather than the entire number itself (if it has digit length greater than one in some base). Thus, beware of grouping. Confer: poi'a'u, jau'au. The attachment of this word to the immediately preceding word can be overridden by the usage of xe'au, which begins bracketing together an utterance/subexpression that will be considered to be the single and whole referent of the clause introduced by this word, the utterance of which also finishes the bracket. There is a proposal to expand the attachment of this word to any word spoken in a mekso utterance (rather than only members of selma'o PA), including members of selma'o VUhU, etc. See also: noi'au.