I hope that someone may be able to help me. I came across this statement in a fare rule:
UNLESS OTHERWISE SPECIFIED 4 FREE TRANSFERS PERMITTED ON THE PRICING UNIT INTERLINE INCLUDING THE PRIMARY CARRIER 2 FREE AT ANY POINT IN EACH DIRECTION. AND - UNLIMITED TRANSFERS PERMITTED ON THE PRICING UNIT ONLINE ON THE PRIMARY CARRIER FARE BREAK SURFACE SECTORS PERMITTED AND EMBEDDED SURFACE SECTORS NOT PERMITTED ON THE FARE COMPONENT.
As I understand it, I'm allowed 4 free interline transfers. So this is transfering from one carrier to another.
More importantly, for MR reasons

, the 'unlimited transfers permitted on the pricing unit online on the primary carrier' means that as long as I follow the (very generous) routing guidelines as given for the rule, then I can max out my journey. I am also presuming that one has up to 23h 59min to make the transfer.
Any help gratefully received!!