That question is muddled, but I refer you to Condition 14 of the National Rail Conditions of Travel (or read our Fares Guide) for full details; if any part of it needs clarifying feel free to create a thread in Fare Advice & Policy. The point is that if tickets are valid under the NRCoT, they must be accepted. Not all staff understand the NRCoT; that's fine providing they accept the tickets. If you're unsure, you can't bring your employer into disrepute by breaching the contract. I am aware of multiple incidents; I have had many of these described to me and I have seen the tickets held were valid. It is an undeniable fact that the vast majority of the allegations that have been posted here are indisputably true. And also let's not forget this point: If I had been guilty of some of the poor behaviour exhibited at the Euston gateline, the excuse that 'most people I interacted with were satisfied' would not wash.