RN Numbers

Where did that one formula come from?

If you’ve done any internet searches on identifying and dating vintage clothing, you’ve probably seen RN numbers mentioned. Despite popping up in dozens of blog articles, webpages, and even YouTube videos, it was surprisingly tricky to find the original sources for where all this information was coming from. I did a little digging to get the specific details on how RN numbers are assigned, what they mean for dating vintage, and who created that oft-repeated RN calculation formula.

According to the official Federal Trade Commission website, “RN stands for Registered Identification Number. It is a number issued by the FTC to U.S. businesses that manufacture, import, distribute, or sell products covered by the Textile, Wool, and Fur Acts. Businesses can use this number on product labels instead of the company name.”