A restricted procedure is a two-stage process: suppliers first apply to be shortlisted based on selection criteria, and only those invited may submit a full tender. It limits the number of bidders the authority evaluates in detail.
The first stage assesses capability and eligibility; the second invites shortlisted suppliers to bid on price and quality. This suits complex requirements where the authority wants to reduce evaluation effort or protect sensitive information, at the cost of a longer overall timeline.