Article 2
This Convention shall apply to documents which have been executed by diplomatic agents or consular officers of a Contracting Party, acting in their official capacity and exercising their functions in the territory of any state, and which have to be produced:
either in the territory of another Contracting Party, or
to the diplomatic agents or consular officers of another Contracting Party exercising their functions in the territory of a State which is not a party to this Convention.
This Convention shall also apply to official certificates, such as those recording the registration of a document or the fact that it was in existence on a certain date, and authentications of signatures, appended by diplomatic agents or consular officers to documents other than those referred to in paragraph 1.
Мне кажется, в последнем абзаце речь идёт как раз о всяких свидетельствах. Но чтобы понять, к чему относится распространённое определение ", appended...", ко всему абзацу или только к "signatures", нужен юрист