Paul Oter wrote:

In what sense is it TOC-specific? Day Travelcards from Cambridge to KX
aren't TOC-specific.

If it still exists (and it's not on the FCC site so maybe it doesn't),
I'm fairly sure it is/was routed THAMESLINK. That makes it
TOC-specific. Thameslink were the only TOC I am aware of that had such
a product (an outboundary First Class ODTC), and I have not heard of
another since.

Similarly, a Standard Class ODTC from Milton Keynes (like the one I
used today) can either be routed Any Permitted, or for less money
SILVERLINK ONLY. The former isn't TOC-specific (as far as BZ6), the
latter is.

Neil