In our DO, everyone gets training (shown around) for a new walk without exception. That's the official policy. It's simply not good enough to make someone do the added 1/3 of a neighbouring duty without knowing the route because it would take far too long to figure it out by themselves when already pressured by time constraints on the duty that they do know. Often the bits added on won't be directly neighbouring areas anyway and will require a bit of driving to get there.
In an office where everyone gets shown around a duty, it is absolutely right that anyone now having to do the added bits as part of DM26 gets shown around the walk. Why shouldn't they?
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