This part of ISO 6520 serves as the basis for a precise classification and description of weld imperfections. In order to avoid any confusion, the types of imperfection are defined with explanations and illustrations where necessary. Metallurgical imperfections are not included. Another system for the designation of imperfections is possible, according to ISO/TS 17845. Annex B gives the correspondence between the existing classification of imperfections according to ISO 6520-1 and the designation system according to ISO/TS 17845. NOTE In addition to the terms and definitions used in two of the three official ISO languages (English and French), this part of ISO 6520 gives the equivalent terms and definitions in the German language; these are published under the responsibility of the member body for Germany (DIN). However, only the terms and definitions given in the official languages can be considered as ISO terms and definitions.