If the buyer has a clear and unambiguous description or specification, and wants to find out which supplier can deliver the best value when and where needed, they will typically issue a

a$.$ request for bid $($RFB$)$

b$.$ request for information $($RFI$)$

c$.$ request for price $($RFP$)$

d$.$ request for quotation $($RFQ$)$

e$.$ request for proposal $($RFP$)$