(28)This Directive should not apply to certain emergency services where they are performed by non-profit organisations or associations, since the particular nature of those organisations would be difficult to preserve if the service providers had to be chosen in accordance with the procedures set out in this Directive. However, the exclusion should not be extended beyond that strictly necessary. It should therefore be set out explicitly that patient transport ambulance services should not be excluded. In that context it is furthermore necessary to clarify that CPV Group 601 ‘Land Transport Services’ does not cover ambulance services, to be found in CPV class 8514. It should therefore be clarified that services, which are covered by CPV code 85143000-3, consisting exclusively of patient transport ambulance services should be subject to the special regime set out for social and other specific services (the ‘light regime’). Consequently, mixed contracts for the provision of ambulance services in general would also be subject to the light regime if the value of the patient transport ambulance services were greater than the value of other ambulance services.