What height must telephone numbers be posted at the outlet for visibility?

The correct height for telephone numbers to be posted at the outlet for visibility is 3/4 inch. This specific height ensures that the numbers can be easily read by anyone who may need to contact the outlet in an emergency or for service-related issues. Having the numbers at this size balances visibility and practicality, ensuring that they remain legible from a distance while still complying with safety and regulatory standards.

It is important for signage, especially in contexts involving gas outlets, to adhere to established guidelines to promote safety and accessibility. Clear visibility of contact information is vital for facilitating a quick response in urgent situations. Hence, 3/4 inch is the prescribed measurement that helps achieve these objectives.