"Standing down cookies" (often referred to as Cookie De-duplication) is the process where if a sale had already tracked with an affiliate cookie and another affiliate link is clicked the second affiliate cannot overwrite the original sale.
It is used for affiliate types that appear really end of the funnel and can easily overwrite existing affiliate sales. Its often commonly used for browser extentions as they pop up in the checkout, and an affiliate can already have introduced the sale. The last click model traditionally would make it unfair to reward these partners and allow other traffic to be overwritten.
