1.1 This European Prestandard specifies information objects and services to be used when transferring information between medical imaging modalities and information systems in a healthcare environment. 1.2 This European Prestandard does not specify the information or usage domains of particular modalities or information systems as these vary according to local and national practices. 1.3 This European Prestandard only applies to information sent between a modality and an information system in the form of a worklist, in response to a request from that modality. It provides: - a description of the content of the messages that transfer the worklist information and - a communication mechanism to transfer these messages. 1.4 This European Prestandard is applicable only to character-based (i.e. alphanumeric) information. It does not apply to information presented as images or graphics. 1.5 This European Prestandard does not cover information objects and services to be used when transferring administrative, request, report and diagnostic service plan information between DISs (of imaging departments) to or from HIS. This is covered by CEN/TC 251/PT3-022.