Seeking info on an award document

[lakesidetrader]

Can someone tell me what the "ON." means on this guys award document for his name? Thanks in advance for your help.
Paul

[Yubari]

his kriegsmarine personal number, same as on dog tag.

[glaser]

Hans Loewe was first attributed to a Northsea Unit and had the number N.(orthsea) 35224/42 and afterwards he was transferred to an Ostsea Unit and they added the O(stsea) to his number, resulting in his new personal number ON. 35222/42

[lakesidetrader]

Thanks ALL