I.S. CEN TR 1749:2006

Foreword
1 General scheme
  1.1 Type A
  1.2 Type B
  1.3 Type C
2 Supplementary classification scheme for type A and type
  B appliances fitted with particular safety devices
3 Supplementary classification scheme for type B appliances
  for use in limited installation conditions
  3.1 Type B appliance utilising a third subscript 'D'
  3.2 Type B appliances utilising a third subscript 'P'
      3.2.1 Type B appliances without draught diverters
      3.2.2 Type B appliances with draught diverters
4 Supplementary classification scheme for type C
  appliances for use in limited installation conditions
Annex A (normative) Classification according to
        the mode of evacuation of the products
        of combustion
Annex B (normative) Special national appliance
        classification (types)
      B.1 Austria and Germany