Abstract: A mounting assembly includes an elongated mounting bracket and an elongated retention bracket. The mounting and retention brackets are configured for ridged attachment to the side of a structure, such as by bolts. A coupling channel extends along the length of the mounting bracket and communicates with the exterior through a narrow mouth. The coupling channel is configured to slidably receive and retain the top edge of a display sheet. The retention bracket has a plurality of spaced apart holes transversely extending therethrough. Each hole is configured to receive a corresponding spring. Each spring has a first end configured for attachment to the bottom edge of the display sheet. Once the spring is attached to the display sheet, the second end of the spring is passed through the corresponding hole on the retention bracket. A pin is then secured to the second end of the spring, thereby securing the display sheet between the mounting bracket and the retention bracket under the biased tension of the springs.