To indicate the source of goods and services, which of the following is used?

The use of trademarks is fundamental in helping to indicate the source of goods and services. A trademark serves as a distinctive sign that identifies products or services from a particular source and distinguishes them from those of other vendors. This identification helps consumers to associate their purchasing decisions with quality and brand reputation, facilitating brand loyalty and trust.

Patents, while they protect inventions or processes, do not function to indicate the source of goods and services. They focus on the protection of intellectual property rather than branding or customer recognition aspects. Waivers and indemnity clauses are legal instruments that relate to liability and risk management in agreements but do not serve the purpose of signifying the source of products or services in the marketplace. Therefore, trademarks are the correct choice for indicating origins in commercial contexts.