A dedication plaque is a metal plate found on the bridges of most Federation starships. The information on the plate has varied over the years, but most often lists the name of the ship, the registry number, the class of the ship, the ship yard of origin, and a quote from a historical figure. Some plaques also include a listing of the officers involved in the construction of the ship.
Some dedication plaques were not placed on the bridge, nor specifically for the ship itself, but for other memorable people and locales on a starship. By approximately 2294, John Harriman had a plaque dedicated to James T. Kirk installed on the USS Enterprise. It was in the area of the ship where Kirk was (at the time) believed to have been killed. (ST comic: "Spock: Reflections, Issue One")