What is an Apostille Stamp ?
An Apostille Stamp or Apostille as it is called sometimes, is nothing more than an official stamp that will guarantee that a document is original.
Fx. a doctor who is working in Greece may need to have his degree certificate from the UK apostilled,to prove that it is from a public university.
The specific and exact rules regarding apostille stamps are definded in the Hague Convention. All documents have to be certified in the country where they were issued. And they only have to be certified, if they are being used in a country that has signed the Hague Convention.
Example of an Apostille:
More information about apostilles can be found on this resources:
http://en.wikipedia.org/wiki/Apostille_convention
http://www.hcch.net/index_en.php?act=conventions.text&cid=41