It seems rather that the spec allows, but doesn't require, lenience in what data the encoder accepts. If you want to write an encoder that always errors when gi

It seems rather that the spec allows, but doesn't require, lenience in what data the encoder accepts. If you want to write an encoder that always errors when given invalid data (that is always "strict"), that's fine. But if you're going to be liberal in what you accept, you are required to also implement a strict mode.