Regulation (EC) No 223/2009 of the European Parliament and of the Council, of 11 March 2009, on the transmission of data subject to statistical confidentiality to the Statistical Office of the European Communities.

Statistical surveys are those that have received the approval set out in article 2 of the Law no. 51-711 of 7 June 1951 on Obligation, Coordination and Secrecy in Statistical Matters and which are included in the list of official statistical surveys published in the Journal Officiel each year.

The only rule imposed by statistical secrecy is the impossibility of direct or indirect identification. In practice, statistical secrecy is considered to be upheld if the knowledge of a characteristic relating to an individual cannot lead to the knowledge of another characteristic with which it is cross-referenced in a table.

The files are rendered totally anonymous insofar as they do not allow for the identification of the retail outlets, the urban units in which the price collections are carried out or the details of the consumption segments included in the calculation of the price index. The published aggregated data do not allow for this identification. The data made available to researchers on an occasional basis are completely anonymised.

The list of the retail outlets in which the prices are surveyed are secret and are not transmitted outside INSEE, or even within INSEE, other than to the units responsible for calculating the price index.