Question about an advance ticket that doesn't specify exact trains

[Xenon]

I have an advance ticket from Wilmslow to Winchfield which simply says "From Wilmslow *" and "To Winchfield *", but the validity says "BOOKDTRAINONLY". Only 1 reservation coupon was included for the train from Wilmslow to London Euston, so, here's my question question: how would they know if I was on the trains I booked going from London Waterloo to Winchfield?

 

[yorkie]

You may take any appropriate train from London Waterloo.