LTI taxis: we use TX1 but according to a book comment it should be TXI. The story is that when the prototype was unveiled to senior management it was labelled TAXI as the name was undecided as Fairmile was the best anyone could come up with. The Seniorest Manager simply got out his Big Senior Management pen and crossed out the A so it became TXI.

No idea if this has been spotted or discussed before, but if agreed it should be a simple block update. However everyone seems to quite happily use TX1 (eg wiki, google references etc). Doesn't affect its successor TXII or its successor's successor TX4.