LE PRÉSIDENT DU CONSEIL, MINISTRE DE LA GUERRE
CITE
À L’ORDRE DE L’ARMÉE
LA VILLE DE PARIS: CAPITALE MAGNIFIQUEMENT DIGNE DE LA FRANCE, ANIMÉE D’UNE FOI PATRIOTIQUE QUI NE S’EST JAMAIS DÉMENTIE, A SUPPORTÉ, AVEC UNE VAILLANCE AUSSI FERME QUE SOURIANTE DE NOMBREUX BOMBARDEMENTS PAR AVIONS ET PAR PIÈCES À LONGUE PORTÉE. A, DE 1914 À 1918, AJOUTÉ DES TITRES IMPÉRISSABLES À SA GLOIRE SÉCULAIRE.
PARIS, LE 28 JUILLET 1919
GEORGES CLEMENCEAU

The sign on the Paris City Hall was placed after World War I, with the signature of Georges Clemenceau, Minister of War and President of the Council of Ministers.
The sign indicates the city’s brave resistance to the bombings it suffered during the war, and as a result, the war cross (Croix de Guerre) was added to the city’s Coat of Arms.

The town hall was photographed on the same day Click for a larger image

Translation of the text on the sign:
THE PRESIDENT OF THE COUNCIL, MINISTER OF WAR
QUOTED
TO THE ORDER OF THE ARMY
THE CITY OF PARIS: A MAGNIFICENTLY WORTHY CAPITAL OF FRANCE, ANIMATED BY A PATRIOTIC FAITH WHICH HAS NEVER FAILED, HAS SUPPORTED, WITH A VALIANCE AS FIRM AS SMILY, MANY BOMBARDS BY PLANES AND LONG-RANGE AROUNDS. A, FROM 1914 TO 1918, ADDED IMPERRISHABLE TITLES TO HIS SECULAR GLORY.
PARIS, JULY 28, 1919
GEORGES CLEMENCEAU