Hitlerjugend: An In-Depth History: Unit identification system
by Arvo L. Vercamer

Numeric HJ unit designations: Orignially, the numbers intended to intentify a specific HJ unit were supposed to correspond to all of the regiments within the German Wehrmacht. However, as the number of regiments increased faster than the HJ units did, especially once the war broke out in 1939, this system quickly fell into a serious state of dissaray.

Use of Arabic numerals: Located on either the flags or on the shoulder straps, a number such as 120/7 would represent Gefolgschaft 7 of Bann 200. Sometimes Latin or Gothic scripted letter would preceed the Gefolgschaft number, such as "Na" for Nachrichten-Gefolgschaft (signals unit) 7 of Bann 200.

Use of Roman numerals: Located on either flags or on the shoulder straps, a number such as II/127 would represent Unterbann II of Bann 127. Sometimes Latin or Gothic scripted letter would preceed the Gefolgschaft number, such as "Na" for Nachrichten-Unterbann (signals unit) II of Bann 200.