What identification sign should be hung on the protective door of elevator shaft?

Yellow and black stripes. According to relevant public information, according to the description of the relevant standards in "Safety Skills Specification for Working at Height in Building Construction", the protective railing and gate grille at the elevator wellhead should be marked with yellow and black stripes. The elevator shaft is used to install the elevator, and the size of the shaft depends on the choice of elevator. The elevator track and counterweight track are installed on the shaft wall, the elevator door is installed in the reserved doorway, and the elevator machine room is located at the top of the shaft.