The boundaries of the Devonian, Carboniferous, and Permian stages of the Global Stratigraphic Reference Scale (abbreviated to Global Stratigraphic Scale-GSS) are described in relation to the biostratigraphic and/or lithostratigraphic units of the Regional Stratigraphic Reference Scales (abbreviated to Regional Stratigraphic Scales-RSS) of Central and West Europe, East Europe, Tethys, South China (eastern Tethys), and North America. In their type regions the boundaries of GSS units rarely coincide with those of homonymous RSS units. Moreover, the definitions of some RSS units have changed several times over the last decades, and subsequent misunderstanding of the stratigraphical significance of these changes has often introduced errors into ...