1.1 This practice defines CODEN, how to obtain them, and how they can be used or applied. 1.2 The rules for establishing or selecting the publication title to which a CODEN is assigned, as well as the rules for establi This practice defines the proper ways of obtaining, and using or applying CODEN. The rules for establishing or selecting the publication title to which a CODEN is assigned, and the rules for establishing CODEN, are not contained here.