It is always necessary to legalize the documents?

The Brussels Convention, signed at 25 May 1987, provides for the abolition of legalisation of documents in the member States of the European Communities (ratified in Italy by Law n. 106, of 24 May 1990). The abolition of legalisation gives the desirability of ensuring the free movement of documents between States parties and of adopting uniform rules concerning the abolition of all forms of legalization of documents or other equivalent procedure. The following states have ratified the convention: Belgium, Denmark, France, Italy and Ireland. This Convention shall apply to public documents which are drawn up in the territory of a contracting State and which have to be produced in the territory of another contracting State or shown to the diplomatic or consular agents of another contracting State even if those agents are acting in the territory of a State which is not a party to this Convention.
This Convention shall also apply to documents drawn up in their official capacity by the diplomatic or consular agents of a contracting State acting in the territory of any State, where such documents have to be produced in the territory of another contracting State or shown to the diplomatic or consular agents of another contracting State acting in the territory of a State which is not a party to this Convention.
If the authorities of the State in whose territory the document is produced have serious doubts, with good reason, as to the authenticity of the signature, the capacity in which the person signing the document has acted or the identity of the seal or stamp, they may request information directly from the relevant central authority.
Article 6 of the text states that the Convention shall be open for signature by the Member States of the European Communities. It shall be subject to ratification, acceptance or approval. This Convention shall enter into force 90 days after the deposit of the instruments of ratification, acceptance or approval by all the States which are members of the European Communities at the date on which this Convention becomes open for signature. This Convention shall be open for accession by any State which becomes a Member of the European Communities and shall enter into force for any State acceding thereto 90 days after the deposit of its instrument of accession.
Each Member State may, at the time of signature, specify the territory or territories to which this Convention shall apply.