Four features ensure the complete security of civil status documents. They are printed on the back of the document:
All or part of the figure below is visible when the paper is held in front of a light source.
Chemical indicators incorporated in the paper cause rings to appear when the paper is exposed to ink solvents.
Unbroken fine blue lines are embossed at the top of the document, giving an effect of relief and abrasive to the touch.
When the document is held horizontally at eye level, a fleur-de-lis can be seen in the top right corner of the engraving. This image cannot be reproduced by a photocopier.