Cant Identify a component of the intake manifold

[amyasin]

I am putting my motor back together. As I double check the vacuum hoses in the intake manifold and determining what to block off I located the following tip off of the bottom of the intake manifold. I am not sure whether it needs to be capped off or not. From what i have read I think it was a component of the A/C heater system which was removed. Is it ok to block off?

Thanks in advance

[HughJazz]

The rubber hose from your brake booster goes there