By confirmed, irrevocable, transferable and divisible L/C to

By confirmed, irrevocable, transferable and divisible L/C to be available by sight draft to reach the sellers before ___/___/_____ and to remain valid for ingotiation in China until 15 days after the aforesaid time of shipment. Tje L/C must specify that transhipment and partial shipments are allowed.
中的ingotiation什么意思？