Yes. The restriction code for a Whitby to Manchester Stns SVR is 2M and Break of Journey is permitted on both legs.I'll be travelling Whitby to Manchester soon, with an 'off peak' ticket. Can I break the journey at York (which we stop at) to look in at the NRM?
Wilmslow, not Manchester?
In that case the restriction code is not 2M; it's 8A. This is valid "on any train" however you are not officially allowed to break your journey (ie, leave station premises other than to connect with a train from another station etc...) on the outward portion.
Reading between the lines yes, it had been assumed the OP held a Whitby to Manchester Return, but now it appears to be a Wilmslow to Whitby Return. Changing one of the stations and the direction can completely change the validity of a ticket (indeed just one of those can completely change the validity!) If a question is asked about a specific ticket, we really do need to know exactly what ticket it is to be able to advise.So the OP should be fine stopping at York on the return half (of a Wilmslow to Whitby SVR), which seems to be what is proposed here.
There seem to be some arcane ond overly complex rules regarding rail ticketing. Why on earth should it make any difference if I start my journey at Manchester or Wilmslow (starting from Wilmslow entails going via Manchester, so from Manchester onwards the two journeys are identical).
This forum would be a lot less busy if the same restrictions applied to all tickets of a given type!