Confusion about Immediate

[percybolmer]

Hey, I am writing a blog post about RabbitMQ in Go, and once doing this I really try to dive deep into understanding everything.

I am a bit confused about the immediate parameter in the Publish functions, that accepts an Immediate flag.
Is this left for backward compatibility and can be ignored if using RabbitMQ v3+?

I've noticed that immediate is removed after that.
https://blog.rabbitmq.com/posts/2012/11/breaking-things-with-rabbitmq-3-0