The proposed work item will aim to develop an International Standard to define the characteristics of a categorial structure for human anatomy to be used by the healthcare terminological systems with the minimal domain constraints they shall be conformant with for binding these terminologies to the information model of EHR,in order to support the exchange of meaningful information between different EHR using different healthcare terminological systems using human anatomy and different national languages. Categorial Structures supports interoperability by providing common frameworks with which to a) develop terminological systems that are able to be related to each other and b) to analyse the properties of different terminological systems to establish the relationship between them. This standard is applicable to: - organisations involved with the development or maintenance of terminological systems as defined in ISO 17115 2007 and based on human anatomy namely for multipurpose coding systems on a national or international level - organisations developing and maintaining software tools allowing natural clinical language expressions analysis, generation and mapping to the main existing healthcare terminological systems. The European standard EN 15521 2007 will be used as a starting document in relation with his revision within CEN TC 251 .It is intended for use as an integrated part of computer applications and for the electronic healthcare record.The standard itself is not suitable for or intended for use by, the individual clinician or hospital administrator.