I was reading this article, and found one sentence that I couldn't understand. https://www.quora.com/Is-it-legal-for-Coca-Cola-to-not-reveal-what-is-in-the-recipe/answer/Donald-Pearline
What does this mean? "At the plant level we received cartons with four no. 10 tins of Seven X per carton, unlabeled except as Seven X." mean