This report comprises the final definition of communities encountered on the shingle substrate and their relation to existing communities identified by the National Vegetation Classification. It forms part of the wider study of the vegetation of shingle structures in Britain, the results of which are presented in separate appendices to this report for detailing individual coastal shingle sites in England, Scotland and Wales. This work was conducted within the framework of the National Vegetation Classification (NVC) in order to assess the applicability of existing NVC categories to the shingle communities and, where appropriate, to extend the NVC by highlighting any new communities identified