Separate top-level sumti or selbri.
This optional, elidable marker can be used to force terminators in order to conveniently return to the top-level / main bridi e.g. to add a modal, tense, or other sumti at the end of a sentence after a deep right-branch. It does not require anything on either side, but if there is, the right-hand side must be at the top-level (thus forcing terminators in order to return to the top-level). It also can force vau terminators for GIhA. It can also be used as an idiom to append UI at the end of the sentence while attaching emphasis on the whole sentence, e.g. with «cu'e'o(vau).ui».