Blue plaque 蓝色牌匾
A blue plaque is a permanent sign installed in a public place in the United Kingdom and elsewhere to commemorate a link between that location and a famous person or event, serving as a historical marker.
The world's first blue plaques were erected in London in the 19th century to mark the homes and workplaces of famous people. This scheme continues to the present day, having been administered successively by the Society of Arts (1867–1901), the London County Council (1901–1965), the Greater London Council (1965–1986), and English Heritage (1986 to date).