Whoever allows TOCs etc., to raid offical class numbers and destroy the credibility of the scheme needs to be seen to. It's almost as bad of OFCOM's handling of phone numbering, except that only those professionally involved with the railway really need to understand TOPS numbering. Oh yes, then there's the spotters to keep happy.
What I don't understand is what happened to all trains from the same family having close-together numbers (in different ranges to denote different traction if needed)
PEP stock: 313, 314, 315
Mk3 based EMUs: 317. 318, 319, 320, 321, 322
Sprinters: 150, 153, 155, 156, 158
Networkers: 165, 166, 365, 465, 466
Voyagers/meridians: 220, 221, 222
But then...
Desiros - 350, 360, 380, 444, 450, 700, 707, 717
FLIRTs - 745, 755, 777
Aventras - 345, 701, 710, 720, 730
AT3000s/IETs/Azumas/Whatever you want to call them: 800, 801, 802 (goood....), 803 (well done!), 805 (what happened to 804?), 807 (what happened to 804 and 806?), 810 (what??)
It seems like a sensible logical numbering has gone out of the window and either TOCs or manufacturers are being allowed to just classify their trains wherever they like in the system. I know it's not the biggest problem in the world, but still. We had a good system and then we lost it. And that irritates me.