A simple and easy to use triaxial recording system intended for use in clinical, educational and research activities which aims to ensure that disabilities and factors relevant to the management of a mentally ill patient's condition are systematically recorded. It has been prepared and trialled by an international team of experts and has proven easy to use, helpful and applicable to a wide range of cultures and settings. This comprehensive manual provides information on the development of the ICD-10 multiaxial system and describes its structure and use. It details ICD-10 categories for each axis of the system as well as instruments and instructions for their application. The instruments include the ICD-10 multiaxial diagnostic formulation form, WHO short disability assessment schedule (WHO DAS-S) and Axis III checklist.