Caution (August 2025) : the loose ledge in the middle of the traverse has been strengthened with a piece of wood and one should verify the solidity of the system before trying this problem.
Sitstart completely right, traverse all the face up to the character "H" as for Annonce Catastrophée (without using the big ledge by convention), come back and exit at the top of the boulder as for Catastrophe Annoncée.