Statistical concepts and description of variables
Article 3
1. Member States shall use the statistical concepts laid down in Annex I. 2. The technical characteristics of variables shall be those laid down in Annex II and refer to: (a) the variable’s identifier; (b) the variable’s name; (c) the modality label and code; (d) the collection unit; (e) the mode of collection; (f) the reference period. 3. The variables for which missing values are not allowed and for which data shall be imputed shall be those identified in the Annex II. 4. All household and personal data shall be linkable for the whole duration of the panel, both for cross-sectional and for longitudinal information.