All procedures for offences against narcotics legislation in France are registered in a national file of offenders against narcotics legislation (FNAILS), managed by the Central Office for the Repression of Illicit Narcotics Traffic (OCRTIS). They are classified as cases of narcotics use, use-and-resale, or (local or international) dealing.
The product mentioned in the file is the "dominant drug", meaning the one mainly consumed by the user or held in the largest quantity by the dealer. When this rule cannot apply, the "hardest" substance is indicated: heroin takes precedence over cocaine, which in turn takes precedence over cannabis, etc.
Only Customs offences settled by Customs transactions and without a report being made, are not included in this file.
Source : ministère de la Justice (site : http://justice.gouv.fr)