In a judgment of 18 February 2015 (n° 230.235), the Council of State pointed out that the formulation of the specifications is important for the evaluation of the regularity of an offer. The discretionary power of the contracting authority shall be reduced if they specify that the attachment of a list of documents is “mandatory”. An offer by which no such documents are attached (like, for example, an annex provided by the contracting authority with respect to the costs of all security measures) should be considered as irregular (even if a similar document is attached but doesn’t correspond (entirely) to the annex provided by the contracting authority). The contracting authority cannot conclude that any other information can be used in place of this document and, ultimately, not lead to substantial irregularity. The contracting authority must therefore be vigilant in the way it specifies its specifications, in order to avoid these (severe) consequences.