In the main text ISO 16505:2015 defines magnification values for class II and IV mirrors derived from front-mounted mirrors. However, ISO also points out that there are vehicles with side-mounted mirrors on the road that typically have higher magnification values and recommends to use these higher values (given in Annex B) for these vehicles. 
IGCMS settled on only one value for all vehicle types that is the higher value for class IV and an in-between value for class II.