Every outside window in a building used for manufacturing purposes or for storage which opens directly on any hoistway or other vertical means of communication between two or more floors in such building, shall be plainly marked with the word “SHAFTWAY” in red letters at least six inches high on a white background; such warning sign to be so placed as to be easily discernible from the outside of the building. Every door or window opening on such shaftway from the interior of the building, unless the construction of the partition surrounding the shaftway is of such distinctive nature as to make its purpose evident at a glance, shall be similarly marked with the warning word, “SHAFTWAY” so placed as to be easily visible to any one approaching the shaftway from the interior of the building.
(Prior Code, § 11-16)