This unification concerns only the distinction of non-bogie diesel locomotives for company service on ordinary gauge public and private railways into light, medium and heavy types and the main characteristics that they must present. 2 All other characteristics are not bound by this unification.
UNI 4970-1962 history
1962UNI 4970-1962 General gauge trailerless diesel locomotives for corporate service on public and private railways. Types and main features