AbstractThe13C n.m.r. spectra of the title polymers have been completely assigned for a comprehensive range ofciscontents (σc= 0–1) and head‐tail bias (HT/(HH + TT) = 1 −∞). In the unsaturated polymers (II),cisHH dyads are never found, so that all‐cispolymers are also all‐Ht, butcisTT dyads are formed incis‐transpolymers, equal to the difference betweentransHH andtransTT. The olefinic region consists of seven triplets; two each fromcisHT andtransHT, and one each fromcisTT,transTT andtransHH. In the case oftranseach triplet consists of a main centre peak due totttandctcsequences and two wing peaks due tottcandcttsequences, as defined in the text. The upfield peaks also showcc/ctortt/tcsplittings as well as HH/HT or TT/TH splittings in most cases. In the saturated polymers C6is sensitive tom/rring dyad sequences. A corrected assignment is given for the hydrogenated polymer