heterochain polymer

A class of polymer in which the main chain is constructed from atoms of two or more elements. Heterochain polymers are named by placing the names or symbols of all the elements in the main chain, immediately before the expresssion '-chain polymer', e.g. (oxygen, carbon)-chain polymer or (O, C)-chain polymer; (oxygen, nitrogen, carbon)-chain polymer or (O, N, C)-chain polymer.
Purple Book, 1st ed., p. 146 (http://old.iupac.org/publications/books/author/metanomski.html)