This part of IEC 61156 which is a sectional specification applies to Capability Approval requirements for cables for digital communications in work area wiring according to IEC 61156-1 and IEC 61156-3. Clause 2 is related to the content of the Capability Manual. Clause 3 is related to the Quality Plans. Clause 4 is related to the maintenance of Capability Approval. NOTE Quality assessment belongs to the negotiation between customers and manufacturers. The following clause intends to be a guide when there is a request for a third party Capability Approval. However, it may be used also as the basis for second party or self-certification.