Each proposal contains all certifications and affidavits, a proposal signature sheet and a proposal bid bond. PREQUALIFICATION. General Contingency: This bid shall include in the Base Proposal a construction contingency allowance of Twenty five.Instructions: The sealed envelope is to be labeled with the project name, company name and address, bid package number and description. ABOUT IDOT PROPOSALS: All proposals are potential bidding proposals. These forms must be filled out, signed, and returned in a sealed envelope, or your bid will not be considered.