[Weird] Technical train names like d456gh

In the same spirit as text on things I am always impressed by strange named (like in scifi movie, you got BH345 or fg-54-hjgk). Here are french train names that I find interesting:

Z5300 MI79 - Z8200 Z5600 Z20900 Z6100 TGV Duplex Z6300 TGV PSE Z7100 Z3400 Z23001 Z7300 (Z2) MF67 RATP MF77 RATP Z107