> So one allows adding a repeated/optional field to a schema without re-encoding any messages, Hmm don't they both allow that? Or am I misunderstanding what yo

> So one allows adding a repeated/optional field to a schema without re-encoding any messages, Hmm don't they both allow that? Or am I misunderstanding what you mean here? I guess the interesting (though only occasionally useful) thing about protobuf is if you concatenate two serialized messages of the same type and then parse the result, each repeated field in the first message will be concatenated with the same field in the second message.