In the context of trademarks, this expansion has been driven by international efforts to harmonise the definition of "trademark", as exemplified by the Agreement on Trade-Related Aspects of Intellectual Property Rights ratified in 1994, which formalized regulations for IP rights that had been handled by common law, or not at all, in member states. Pursuant to TRIPs, any sign which is "capable of distinguishing" the products or services of one business from the products or services of another business is capable of constituting a trademark.
What is any sign which is capable of distinguishing one business's product from another business's? (If the question is unanswerable, say "unanswerable")
a trademark