Envelope for interiview ?

[Jeffy14]

Hello,

I read on many post that people would go at the interview with a UPS/FedEx enveloppe to give to the consular officier. I think it is used to send the passport.
However, I cant find anywhere the info that says that we need to bring an enveloppe.
In step 3 and 4, it does not say it.
http://www.travel.state.gov/visa/visa_4760.html

So is the enveloppe still required?

Thanks a lot!!