Is your feature request related to a problem or challenge?

Determining what is the "correct behavior" comes frequently deciding how a function should behave and there is disagreement across implementations (e.g. postgres does something different than spark and/or duckdb)

This happened most recently here with @comphead and @jayzhan211 and @Kimahriman in #13683 (comment)

Describe the solution you'd like

I don't think our codebase is super consistent, but I think it would help to at least document our shared understanding of what we are aiming for.

Describe alternatives you've considered

No response

Additional context

No response