Care should be taken not to discard items that have historical significance. The branch may want to add such items to its library or to its archive of historical material.
So I take it that as a gentle reminder has to be taken as a command from the GB, this means don't let any R+F take an old book home, make sure they are sent to the branch. They don't want any 'old light' getting out. Remember many new converts and newly adult born-ins know nothing about the 1914, one generation to paradise prophecies.