There are three general settings:
This determines whether the lookup should always be performed, or whether it should be bypassed if the Table already contains matching records. Default is 'Always'.
This is useful if the lookup is being performed in response to a user search. By bypassing the lookup when the information is already to hand, the site saves the time and resources needed to perform the lookup, and, if the lookup feed charges per-lookup, can save money.
GET is currently the only request type supported.
XML is currently the only response type supported.