PT002s of TC251 of CEN has been established in order to identify structural elements for classification and coding of surgical procedures. This project team identified 10 types of characteristics that could describe any surgical procedure. These characteristics were grouped in three classes: objects (topography/e.g. body system and body site, pathology, side, material); actions (procedure, extent, numeral) and methods (instrument, material, topography). Syntax-rules are proposed as well as references to existing lexicons.

This structure is mainly addressed to developers of classifications of procedures. It allows retrieval of monoaxial classifications through a multiaxial representation, logical rules for updating, as well as a method to compare existing classification systems. It is still in development and discussion.