Corby station was part of Network Southeast from 1987 to 1990 when it shut (until 2009).
I have to ask, why the line between Bedford and Kettering wasn't also part of Network Southeast? Yes it's not in the Home Counties, but that didn't stop NSE trains in Kings Lynn or Exeter!
And on a related note, why isn't Corby part of the Network Railcard area even though it was briefly in the NSE area? (still to this day it isn't)

Attached is a screenshot of a 1988 Network Southeast map, showing Bedford, Wellingborough, Kettering and Corby. The line between Bedford and Kettering is shown as being "not part of Network Southeast, but served by some Network trains".
I have to ask, why the line between Bedford and Kettering wasn't also part of Network Southeast? Yes it's not in the Home Counties, but that didn't stop NSE trains in Kings Lynn or Exeter!
And on a related note, why isn't Corby part of the Network Railcard area even though it was briefly in the NSE area? (still to this day it isn't)

Attached is a screenshot of a 1988 Network Southeast map, showing Bedford, Wellingborough, Kettering and Corby. The line between Bedford and Kettering is shown as being "not part of Network Southeast, but served by some Network trains".