55While, as the Advocate General states in paragraph 71 of her Opinion, additional information relating to the specifications and any supporting documents, referred to in that provision, may clarify certain points or supply certain information, they cannot change, even by means of corrections, the meaning of the essential contractual conditions, to which category the technical specifications and the award criteria belong, as those conditions were formulated in the specifications, upon which the economic operators concerned legitimately relied in taking the decision to prepare to submit a tender or, on the other hand, not to participate in the procurement procedure concerned. That is apparent both from the very use, in Article 39(2), of the expression ‘additional information’ and from the brief period of time, that is to say six days, allowed between the communication of such information and the deadline for receipt of the tenders, in accordance with that provision.