How far back do you want to go?
From memory:
ET - 616 and 1648
ETZ - 824
ETE - Mark II and NEAX1400
ETW - Electra Professional Level I and Level II
ETJ - NEAX IVS2000
DTU - Elite 48 and 192 (also worked on the Level I and II
DTP - NEAX IPS2000 (also worked on the IVS200)
DTH - Elite IPK and IPK II
DTR - NEAX IPS2000
DTL - SV8100 and SV8300
DTZ - SV9100 and SV9300 - also works on the SV8100
ITR - NEAX 2000 IPS
ITL - SV8100 and SV8300 - have also used on the SV9100
ITZ - SV9100 and SV9300 - works on SV8100 with v9.51 or higher, SV8300 with v9 or higher
Some phones can be mixed and matched if the system software allows. Have used DTU sets on a 2000 and DTP sets on Elite IPK. Others work but can be glitchy. Don't press the "Exit" button on a DTU on a Level I - causes system to reboot
Others may have different experiences. Thought I used to have a compatibility chart from NEC but cannot seem to locate.
I'm not familiar with the NEC/Nitsuko product line so can't help there.
