Legalization of Documents
The legislation of some countries makes provisions for official documents to be legalized.
If that is the case with your country, you have to apply to the competent local authority for the legalization of your study qualification/s (school leaving certificate/diploma; higher education degree/ diploma). The legalization must be performed BEFORE you ask for the Dichiarazione di Valore in loco from the competent Italian diplomatic authority.
If your country signed the Aja Convention of 5 December 1961, you have to request that the "Aja Apostille" stamp be placed on your study qualification/s. The Aja Apostille must be affixed on your degree / diploma BEFORE you ask for the Dichiarazione di Valore in loco.
You are exempted from both the legalization and the Aja Apostille, if your study qualification/s were awarded by an institution belonging to a country signatory to the European Convention of Bruxelles of 25 May 1987 (Belgium, Denmark, France, Ireland, Italy; Italy ratified the quoted Convention by Law 106/1990).
You are also exempted from the above legal procedures in case you hold a German qualification (thanks to the German-Italian Convention on the exemption from the legalization of public deeds - Rome, 16 June 1969; Italy ratified said agreement by Law 176/1973).