The following cmavo are discussed in this section:

How long does a pro-sumti or pro-bridi remain stable? In other words, once we know the referent of a pro-sumti or pro-bridi, how long can we be sure that future uses of the same cmavo have the same referent? The answer to this question depends on which series the cmavo belongs to.

Personal pro-sumti are stable until there is a change of speaker or listener, possibly signaled by a vocative. Assignable pro-sumti and pro-bridi last indefinitely or until rebound with goi or cei. Bound variable pro-sumti and pro-bridi also generally last until re-bound; details are available in Section 16.14.

Utterance pro-sumti are stable only within the utterance in which they appear; similarly, reflexive pro-sumti are stable only within the bridi in which they appear; and ke'a is stable only within its relative clause. Anaphoric pro-sumti and pro-bridi are stable only within narrow limits depending on the rules for the particular cmavo.

Demonstrative pro-sumti, indefinite pro-sumti and pro-bridi, and sumti and bridi questions potentially change referents every time they are used.

However, there are ways to cancel all pro-sumti and pro-bridi, so that none of them have known referents. (Some, such as mi , will acquire the same referent as soon as they are used again after the cancellation.) The simplest way to cancel everything is with the cmavo da'o of selma'o DAhO, which is used solely for this purpose; it may appear anywhere, and has no effect on the grammar of texts containing it. One use of da'o is when entering a conversation, to indicate that one's pro-sumti assignments have nothing to do with any assignments already made by other participants in the conversation.

In addition, the cmavo ni'o and no'i of selma'o NIhO, which are used primarily to indicate shifts in topic, may also have the effect of canceling pro-sumti and pro-bridi assignments, or of reinstating ones formerly in effect. More explanations of NIhO can be found in Section 19.3.