Looking at an older OSS note for IS_Retail I think it is a modification to the standard, at least it was classified as Advance development in 1998, maybe it became standard since then
95434 - WB01: Take over address from customer/vendor
Retail is not my area of expertise, I am only used to Core Industry solution, just browsing some OSS notes returned note 332505 which gives me the impression that WB08 is the standard way to change the site/vendor assignment.
I am moving this discussion to the Retail space where the experts on Retail are.