To damage or vandalize something, especially a surface, in a visible or conspicuous manner.
To alter a coat of arms or a flag by adding an element to it.
To void or devalue; to nullify or degrade the face value of.
To mark a surface with such images.
Drawings or words drawn on a surface in a public place, usually made without authorization.
Informal inscriptions, figure drawings, etc., as opposed to official inscriptions.