This part of IEC 34 specifies the IM code, a classification of types of construction and mounting arrangements of rotating electrical machines. Two systems of classification are provided as folloes: -- Code I (see section 2): An alpha-numeric designation applicable to machines with endshield bearing(s) and only one shaft extension. -- Code II (see section 3): An all-numeric designation applicable to a wider range of types of machines including types covered by Code 1. The type of machine not covered by Code II should be fully described in words. The relationship between Code I and Code II is given in annex A.