This International Standard is one of the IEC 62325-451-x series for deregulated energy market dataexchanges and is applicable to European style electricity markets. Based on the European style market contextual model (IEC 62325-351), this particular International Standard specifies a UML package for the acknowledgment business process and its associated document contextual model, assembly model and XML schema for use within the European style electricity markets. The relevant aggregate core components (ACCs) defined in IEC 62325-351 have been contextualised into aggregated business information entities (ABIEs) to satisfy the requirements of the European style market acknowledgment business process. The contextualised ABIEs have been assembled into the acknowledgment document contextual model.