Retrocession
A commission rebate paid quietly between counterparties, often from a yard or supplier back to a referring broker, captain, or management company. Frequently undisclosed.
Retrocession arrangements are legal in most jurisdictions provided they are disclosed. The structural problem is that disclosure is typically not volunteered. The OnboardOnline legal column has stated the position plainly: retrocession is permitted only where the recipient discloses it to the principal whose interests they represent.