This document provides technical specifications to facilitate an efficient exchange of electronic information between ships and shore, for coastal transit or port calls. It specifies requirements for the safety, security and efficiency enhancement of information, related mainly to the relationships between the ship and the port and coastal state authorities.This document provides the definition of core data elements for use in electronic port clearance (EPC) messages. It does not define any structuring of messages nor provides any guidance on what information is required for a particular purpose; it is a general data dictionary for safety, security or operation-related maritime information. Details about message formats and applications are defined in ISO 28005-1.The data elements in this document is a superset of the data elements and the data model defined in the IMO Reference Data Model as specified in the IMO Compendium on Facilitation and Electronic Business. It also contains data elements from other IMO instruments as described in 4.1. The specifications in this document is compatible with the definitions in the IMO Reference Data Model and the mapping between ISO 28005 and the data element list in the IMO Reference Data Model is defined in Annex B.