Geneva Conventions and United Nations Personnel (Protocols) Bill [Lords]

I wonder whether my hon. Friend could help the House. Who will decide whether the cross or the crystal is used? Will the Foreign Office have a list of sensitive souls who may be offended by the cross, and will it advise aid workers on when to use the crystal, or will someone on the field of battle make that decision? Does he know the answer to that? The Bill does not make it clear.