English to Italian Law/Patents Law: Contract(s) contratto di vendita

Contratto di vendita, condizioni di pagamento:
"For the above mentioned advance payment the Supplier shall provide an irrevocable bank guarantee, issued by a first class bank in favor of the Purchaser in the amount of the respective payment, valid until *initial sign-off*.

Anche nelle condizioni di imballaggio e spedizione:
"The contract goods shall be delivered, and title of ownership and risk of loss on Contract goods shall pass to Purchaser on *Initial Sign-off* at xxxxx Plant".

Grazie per l'aiuto
Manuela