Before it was officially named "Handschar" in mid-May 1944, the unnamed division was given several nicknames by the Partisans and the locals, particularly of the Vojvodina region, where the unit first arrived after the training abroad.
We've already mentioned one, in the section quiz:
Uroš Šuljmanac of the 1st Vojvodina Brigade also mentions the "Plava divizija" nickname, explaining that it was given because of the blue fezzes (this does make sense, although they weren't actually blue, but field-grey). He added that they also called it "Fesaroška divizija" (Fez-Wearers' Division) and "Mujina divizija" (Mujo's Division; for those who didn't know, in Vojvodina, and other parts of the former Yugoslavia, Mujo is a term popularly used for the Muslims - like Fritz or Hans is for the Germans, elsewhere). See Mladost slobodi darovana (ed. by Nikola Božić), p. 112.Ivan Ž. wrote: ↑03 Mar 2019 12:51Indeed, they called it "SS plava divizija" (SS Blue Division). This nickname appears in March-August 1944 documents. Apparently, according to the "Zbornici" staff [which compiled the documents], the Partisans didn't mistake it for another division, but they called it "Blue" because of the blue tassels on fezzes. This doesn't make much sense - not only since the tassels were black - even if they were pink, the chances are extremely low that anyone would nickname a unit by such a minor detail on uniform. So the reason for such a nickname remains unknown.
According to the Syrmian War Crimes Commission, the unit was nicknamed "Mujina divizija" by the (Syrmian) populace, and the commission kept referring to it as such in their 1946 elaborate about (i.a.) the unit war crimes. See Političke vlasti u "NDH" (ed. by Drago Njegovan), pp. 189-192.