Washington — Wal-Mart and a maker of children’s clothes will face off in a U.S. Supreme Court case that could determine the breadth of trade dress protection for product designs.

The high court, which scholars and others say has been supportive of intellectual property protection for two decades, will hear arguments today concerning a question the justices themselves posed to the parties: What must be shown to establish, for purposes of Lanham Act trade dress protection, that a product’s design is inherently distinctive? Wal-Mart Stores Inc. v. Samara Bros. Inc., No. 99-150.