a request, verbal or written, which is made to prospective suppliers for their quotation, tender or offer on goods or services desired by the prospective purchaser, a document which contains an invitation to selected firms to submit tenders, or announcement that tenderers are invited to carry out certain works, document contenant l'invitation d'entreprises sélectionnées à soumettre une offre, ou annonce par laquelle des entrepreneurs sont invités à réaliser certains travaux