The traditional Braun-Blanquet approach and its modern variants are mainly restricted to the classification of phytocoenoses, i.e. assemblages that include all plants (or at least all vascular plants) of the community. How- ever, phytosociologists may also focus on the classification of synusiae – one-layered, ecologically homoge- neous assemblages (e.g., epiphytic or epilithic bryolichenic communities, herbaceous or shrubby fringe com- munities) – using similar class definition procedures. The integrated synusial approach (ISA), developed in Switzerland and France, is an extension of the synusial approaches to the description and classification of phytocoenoses conceived as assemblages of synusiae. Separate plot records are used to build separate consistent classification sections (CCSs) for each category of synusiae, i.e. tree, shrub, herb and moss synusiae. Lower- level synusial vegetation types are called ‘synusial elementary syntaxa’ (SESs). A type-based CCS can eventu- ally be created for the classification of complete phytocoenoses, based on their synusial composition, i.e. lists of SESs. Lower-level phytocoenotic vegetation types are called ‘elementary coenotaxa’.