The respondent is the customer in a correspondent relationship. What the correspondent knows about it comes from due diligence performed at onboarding and periodically thereafter: its ownership, its regulator, its customer base, its expected volumes.
The Wolfsberg Group’s guidance is built around keeping that picture accurate, because the failure mode is gradual. A respondent whose activity drifts away from what it described, or whose customer base has changed without notice, is the ordinary route by which restricted flows enter a clean correspondent chain.