This is called a Copyright Clearance Center (CCC) fee code.
When you request a book via Interlibrary Loan (ILL), the lending library physically mails the book, and eventually receives it as a return. Today, when an article is requested, the lending library scans it and sends the PDF. (It used to be photocopied and mailed). This is far more efficient than mailing the whole journal two ways.
However, because the article is being copied, it may exceed fair use and become a copyright violation. In 1978 the Commission on New Technological Uses of Copyrighted Works studied this issue and provided guidelines on how much copying should be seen as permissible by libraries. The suggested limits include that a library can request five articles per title per year, among other conditions.
When these fair use conditions cannot be met, (e.g. a sixth article is requested) a copyright license must be obtained. The fee code line indicates the publisher has set up a voluntary agreement through the Copyright Clearance Center to collect a $15 royalty for this license. The other information is used by the CCC to identify the article and determine which publisher to remit the fee to. The fee code may be listed on each article, or it may be listed in the printed front matter to apply to all articles. I believe this scheme also applies to certain other library photocopying cases outside fair use, like making a copy for course reserves.
Including the fee in print is from the days before the Internet. The library would make a list of all fee codes that were due and send it with payment to the CCC.
Today, we have online systems. In your example, you can search the DOI through the Copyright Clearance Center Marketplace. If you go through the wizard and select "Report interlibrary loan borrowing", you will see a $15.00 per-copy fee, plus a CCC processing fee.
You can read about this process in the article "Pay-per-view in interlibrary loan: a case study" (J Med Libr Assoc. 2012 Apr; 100(2): 98–103.) This article points out that the listed cost plus CCC service fee is often higher than purchasing the article direct from the publisher.