Reaction in which one or more species of block are connected to the main chain of a macromolecule as side-chains having constitutional or configurational features that differ from those in the main chain.
Source:
PAC, 2004, 76, 889. 'Definitions of terms relating to reactions of polymers and to functional polymeric materials (IUPAC Recommendations 2003)' on page 892 (https://doi.org/10.1351/pac200476040889)