For those of you unaccustomed to the inner workings of the IT business, the RFP (request for proposal) is a formal, written communication to multiple IT vendors.
The use of RFPs used to be nearly universal. These days, you see far fewer of them. Certain kinds of organizations (e.g. public sector) are legally bound to use an RFP process. And you still see the occasional private enterprise issuing RFPs as well.
I get sent a lot of storage RFPs to comment or contribute. And they can be very telling as to what kind of IT organization is creating them.