These certificates are based on the model forms given in Annex G of BS 5839-1:2017 as amended by Annex H of BS 5839-6: 2019+A1:2020 and are to be used for the inspection and servicing of a Grade A system as described in BS 5839-6 within dwellings, supported housing, and the communal areas of HMOs and sheltered housing where the use of a Grade A system is recommended in Table 1 of that standard.