Note 1: In some cases, the dormant polymer may undergo reversible coupling.

Note 2: Initialization usually involves decomposition of an initiator in the presence of monomer and the reagent. Polymerization commences when there is complete consumption of the mediator by initiator-derived radicals.

Examples: Mediators that are proposed to provide control by this mechanism are certain 1,1-diarylethylenes, so-called captodative monomers, and carbonothioyl compounds. This mechanism could also contribute to the degree of control observed in RAFT polymerization.