Commemorative plaque
A commemorative plaque was a type of sign that recalled a notable historical event.

A homemade commemorative plaque was presented to Captain Jean-Luc Picard by Jay Gordon Graas, Marissa Flores, and Paterson Supra in 2368. The plaque was in appreciation of Picard's help and patience while they were trapped in a turboshaft with him after the  was hit by a series of quantum filaments, causing widespread power loss. The plaque's layout roughly resembled that of the Enterprise dedication plaque. 

The plaque read:
To Captain Picard:
In appreciation for the way you helped us get out of the turboshaft, and the way you helped us not be scared.
Jay Gordon Graas
Paterson Supra
Marissa Flores

Patterson was responsible for creating the back piece of the plaque. ()

See also
 Dedication plaque

Awards
Signage