The owner of a foreground may grant exclusive licence to a third party, provided that the other participants agree by written means to waive their access rights thereto.

Such a waiver can only be made on a case-by-case basis, and after the concerned foreground has been generated. Participants should be able to assess carefully which specific access rights they are able or willing to renounce. They should also avoid waiving broader access rights than those exactly required to allow granting such an exclusive licence.