There shall be firmly attached to or painted at or near the point of outlet from which lubricating oil is drawn or poured out for sale or delivery, a sign or label consisting of the word or words in letters not less than one inch in height, comprising the brand or trade name of such lubricating oil: Provided, That if any such lubricating oil shall have no brand or trade name, the above-required sign or label shall consist of the words, "Lubricating oil, no brand."