Earthing Sign - ISO 7010 safety Label. The mandatory sign is a clear and understandable way of communicating a specific safety message. Mandatory symbols are an international recognized and definitive way to display a safety message without words, as defined by ISO 3864. It clearly prescribes specific behaviour (eg: Attach Earthing Point to Ground or Earth System). The mandatory symbols can be used alone or in conjunction with other symbols and written information. Features of the mandatory signs are their round shape, white pictogram on a blue background (the entire symbol component must take up at least 50% of the area of the sign). Earthing Mandatory symbol signs showing the requirement to connect a point to the earthing or ground system. Make safety a loud priority with bright clear reminders, these labels can be placed exactly where they are required.