There are relatively few places on the SWR network where that is the case though - certainly once you are past Basingstoke, Havant, or Epsom the train is unlikely to be going anywhere other than WaterlooNot so sure about this statement, if you are standing on the up platform at Fratton for instance the trains could be heading for any number of destinations in addition to Waterloo - in fact Waterloo is the minority destination, try Southampton, Brighton, London Victoria, Littlehampton or even Cardiff for instance !
Dorking codes for some reason, quite commonly do that.Did someone try to enter a route code, followed by a "/0"?
(The attached file shows a Class 450 on a Dorking service on 14th June, with the display showing "NAN")
Most probably - and just an interesting point as an aside, during engineering works or "special turns", the PIS codes are often omitted from our schedule cards rendering it necessary to manually input the destination and make manual announcements.In November 2025, I saw "1A76 Lon. Wat." on a Class 450 side display (see attachment). Probably a trainspotter guard who entered it?