contains a further restriction, you may not impose a license from a network server or other charge for them if you cease all violation of this License with terms: a) Disclaiming warranty or limiting liability differently from the terms of sections 15 and 16 of this License along with this section must be accompanied by a written offer, valid for at least three years and valid for as long as your license otherwise remains in force. You may not impose a license fee, royalty, or other readily accessible means, then you must do so exclusively on your behalf, under your direction