The four OZ's were designated as Corps Districts Mostar, Tomislavgrad, Vitez and Orašje. Orašje included a much reduced Bosanska Posavina.
The four districts of the OZ (presumably an organization) were named Mostar, Tomislavgrad, Vitez, and Orašje.  Orašje included a considerably smaller portion of Bosanska Posavina.