First, I've searched the old threads on this one. We had a notoriusly difficult inspector fault us for not removing an abandoned power feed. It was an ancient underground feed to a garage that was torn down. The conductors were cut back to the conduit in the disconnect in the adjacent house.
The inspector's quote was that they "need to be tagged for future or removed." He inisisted that we cut the conduit at the foundation where they enter the house.
I inquired about the code and he indicated that it "was finally added in 2005"
I'm familiar with the low voltage removal requirements, etc. but non for power conductors.
Also, do you need a permit to disconnect a feed?