New Zealand World War One Regimental Number Prefixes
https://en.wikipedia.org/wiki/Lists_of_abbreviations_used_on_Commonwealth_World_War_I_medals#Prefix_letters_and_numbers
1/- Samoan Advance Force
2/- Artillery
3/- Medical Corps
4/- Engineers
5/- Service Corps
6/- Canterbury Infantry
7/- Canterbury Mounted Rifles
8/- Otago Rifles;
9/- Otago Mounted Rifles
10/- Wellington Rifles
11/- Wellington Mounted Rifles
12/- Aukland Rifles
13/- Aukland Mounted Rifles
14/- Army Service Corps Divisional Train
15/- Headquarters Staff
16/- Maori Battalion
17/- Vetinary Corps
18/- Chaplains Department
19/- Samoan Relief Force, Infantry
20/- Samoan Relief Force, Mounted Rifles
21/- Army Pay Corps
22/- Nursing Service
23/- 1st Battalion, New Zealand Rifle Brigade
24/- 2nd Battalion, New Zealand Rifle Brigade
25/- 3rd Battalion, New Zealand Rifle Brigade
26/- 4th Battalion, New Zealand Rifle Brigade