 Vertical restraints can take numerous forms, ranging from a requirement that dealers accept returns of a manufacturer's product, to resale price maintenance agreements setting the minimum or maximum price that dealers can charge for the manufacturer's product.So-called "intrabrand restraints" such as resale price maintenance govern products made by a particular manufacturer, while "interbrand restraints" regulate a dealer's or manufacturer's relationship with its trading partner's rivals (e.g., "English clauses").Quintessential examples of interbrand restraints include tying contracts, whereby a purchaser agrees to purchase a second product as a condition of obtaining a so-called "tying" product, and exclusive dealing agreements, whereby a dealer agrees not to purchase products from suppliers that are rivals of the manufacturer.