Originally Posted by
shefgab
You would have to walk between Camden Town tube and Camden Road Overgound....I'm still not sure if "overland sectors" count as a connection....I've only experimented at Kings Cross going from Tube to National Rail where I was charged a weird half fare...
Yes:
http://www.oyster-rail.org.uk/interchanging-trains/
The "weird half fare" may have been the difference between a mixed-mode (TfL+NR) fare and a TfL-only fare. (But travel on NR when there is an equivalent TfL route, known as "interavailability", is also charged at the TfL-only rate.)