PayPal will just log this string. There will NOT be any
business logic around it, nor any decisions made based on
the value of the string that is passed in. From a
tracking/analytical perspective, PayPal would not infer any
meaning to any specific value. We would just segment the
traffic based on the value passed (Cart and None as an
example) and track different metrics like risk/conversion
etc based on these segments. The external partner would
control the value of what gets passed and we take that value
as is and generate data based on it. Optional