Traveller seats

[CheapAndNerdy]

Checking out the seating plan on Virgin Trains' Pendolinios (http://www.virgintrains.co.uk/assets/pdf/global/seating-plan.pdf) some of the seats in first class are marked "traveller seats". What are they?

 

[MCR247]

http://www.virgintrains.co.uk/traveller/

 

[CheapAndNerdy]

http://www.virgintrains.co.uk/traveller/

I thought maybe it was for railway staff. Interesting to know that there is a class of travel just that little bit higher than first.

Thanks