The low glottal tone 
is Toaq's third tone. It is pronounced by inserting a short glottal stop in the syllable's first vowel: tïo is pronounced /tiˀi.o/.
Unlike the other tones, it only occurs on particles, especially those that introduce a subordinate clause, like ꝡä and nä and jü. Its purpose is generally to introduce some sort of recursion or subordination.
Verbs never have the low glottal tone. In fact, pronouncing a multi-raku verb in the low glottal tone would collide with the pronunciation of a prefixed word: *küne would sound exactly like the low allotone of the word kụne in the falling tone.
Thus, to avoid this collision between the pronunciation of and prefixes, regular prefix-taking verbs are never in , and words in are always one raku long. Additionally, words in can't have prefixes. (Or maybe *kụ̈ꝡa is pronounced /kuˀuˀuja/?)