Ciao, credo che si possa trattare di un veto sulla vendita.
Da quel che ne so "cloud" (on title ad es.) è una specie di veto sulla tua proprietà, che ti permette di evnderla solo se trovi un garante. In questo caso che il veto riguardi il diritto del sig. XXX di vendere i prodotti del sig. YYY.
Ho trovato alcune referenze:

***cloud on title (cloud)
n. an actual or apparent outstanding claim on the title to real property. "Clouds" can include an old mortgage or deed of trust with no recording showing the secured debt was paid off, a failure to properly transfer all interests in the real property (such as mineral rights) to a former owner, a previous deed which was improperly written or signed, an unresolved legal debt or levy by a creditor or a taxing authority, or some other doubtful link in the chain of title. Often the "cloud" can be removed by a quiet title action, by finding a person to create or execute a document to prove a debt had been paid or corrected. Title companies will refuse to insure title to be transferred with a "cloud," or they will insure ownership except for ("insure around") the "cloud."***