This CEN Report gives the principles of numerical designation systems for metallic materials already in place and which are falling into a general pattern and gives recommendations for how this general pattern should be used when evaluating designation systems for new metals to be standardized.
DS/CEN/CR 12172:1996 history
1996DS/CEN/CR 12172:1996 Numerical designation systems for metallic materials - Review of existing systems and recommendation for new systems