If your library wants to transmit license information to a vendor, the typical route would be to use a vendor note field.
If your library creates a note on the order item with type Vendor, this will be communicated to the vendor in the EDIFACT order message.
If your library is importing MARC order data to create the order, you can now import the license information directly into the vendor note field using the 981 $v field.
For additional information see Vendors.