This document specifies the definitions and requirements for ancillary fittings and shallow chambers installed underground in non-pressure drainage and sewerage systems and manufactured from unplasticized poly(vinyl chloride) (PVC-U), polypropylene (PP), polypropylene with mineral modifier (PP-MD) or polyethylene (PE) intended for use for: — non-pressure underground drainage and sewerage outside the building structure (application area code “U”), and — non-pressure underground drainage and sewerage for both buried in ground within the building structure (application area code “D”) and outside the building structure.