For example, giving a Hechsher to water that comes directly from filtered water pipes (zero chashash for grapes, etc.). Have you ever heard of “kosher” water??
Another example is a Hashgacha requiring the food manufacturer to use ingredients/coponents only with THEIR Hashgacha. In other words, Hashgacha Gimmel requiring a muffin manufacturer to use flour, sugar etc etc with Gimmel, and not from equally-reliable Daled. That is not Halacha, that is money.