The authentication or similar formalities otherwise required shall be unnecessary when requests for cooperation encompassed by this Convention are transmitted via consular or diplomatic channels or via the Central Authorities, and when conveyed directly from one tribunal to another in the border area of the States Parties. No authentication in the requesting State Party shall be required in the case of related documents returned via the same channels. Where necessary, the requests shall be translated into the official language or languages of the State Party to which they are addressed. With respect to attachments, a translation of the summary of the essential information shall suffice.