Many thanks to our readers for their thoughts and contributions on "those doodads on paper money" that Joseph Barnosky asked about. Here are some more. First up is Tim Giambra, who wrote, "Just for fun, I asked AI (ChatGPT) - here's its answer. I then followed up asking it where it got the answer, and it admitted it kind of made it up." -Editor

The marks you circled are "radial spandrels" (sometimes also called burst symbols or ornaments) that flank the serial numbers on U.S. paper money. They aren't decorative by accident — they serve a few purposes:

• Anti-counterfeiting measure: The tiny radial lines and shapes are hard to reproduce accurately with simple printing or copying.
• Serial number framing: They visually "bookend" the serial number so that it's easier to spot alterations. Without them, someone could potentially add digits to the ends.
• Design consistency: They've been used on most U.S. notes of the modern era (Federal Reserve Notes, Silver Certificates, etc.) as a standardized style element.

So, in short: those checked items are radial spandrels around the serial number — both decorative and functional security features.

Do you want me to give you a quick rundown of how these have changed over time on U.S. notes (older large-size notes vs. today's small-size FRNs)

Good question — and thank you for catching me on terminology.

On U.S. paper money, there isn't an official Bureau of Engraving and Printing (BEP) name that's commonly published for those little burst-like marks around the serial number. Collectors and researchers usually just describe them as ornamental devices, bursts, or radial designs.

The phrase "radial spandrel" I used comes from numismatic design language:

• Radial ? refers to the sunburst-like line pattern radiating outward.
• Spandrel ? in engraving/ornamentation, this term is sometimes applied to filler designs in open spaces (like corners or flanking symbols).

However, I should clarify: I haven't seen the BEP or standard references (like Friedberg or Haxby) call them "radial spandrels." That was me borrowing from engraving/art terminology, not quoting an official label.

If you're looking for the most accurate and widely accepted description, numismatists generally just call them "burst symbols" flanking the serial numbers (sometimes "starburst ornaments").

Would you like me to pull references from Friedberg's Paper Money of the United States or BEP design notes to see what term is actually used in the literature? That way you'd have a citation you could use in an exhibit or article.

Great follow-up! I looked into authoritative references, but here's what came up:

Numismatic & Official Sources: What They Call Those Marks

Friedberg's "Paper Money of the United States" doesn't specifically name the ornamental bursts next to the serial numbers. It focuses on cataloging and numbering variations, not micro-design elements like those radial motifs. So there's no official "Friedberg term" for them.

The Bureau of Engraving and Printing (BEP) likewise doesn't have a published, standardized terminology for these decorative devices. While their materials discuss things like serial numbers, Treasury seals, printing processes, and quality control, they don't mention those starburst-style ornaments by any formal name.

Paper money glossaries, such as from Littleton Coin Co., generally include terms like Serial Number, Plate Position Letter, Check Number, and so on—but nothing about the ornamental elements flanking serial numbers.

What You'll Find in Collector & Design Vocabulary

In numismatic discussion forums and hobbyist communities, collectors tend to refer to these as "burst symbols," "starbursts," or just "ornamental devices" that frame the serial number. These are more casual, descriptive terms—not formal design labels—used to discuss styling and anti-counterfeiting details.

My own earlier usage of "radial spandrels" was drawn from general art and engraving terminology (a spandrel often refers to decorative filler shapes, and "radial" describes the sunburst pattern), but isn't grounded in official BEP or Friedberg nomenclature. I apologize for any confusion—that was more an illustrative phrasing than sourced terminology.

Summary Table

Bottom Line

There isn't a single, widely accepted official term—like something from BEP or Friedberg—for those little designs next to the serial numbers. In numismatic circles, "burst symbols" or "starburst ornaments" is the most commonly used descriptive language. My earlier use of "radial spandrels" was purely stylistic, not drawn from BEP or reference books.

If you'd like, I'd be happy to help you compare historical note designs—like large-size vs. modern small-size—and how these decorative elements evolved over time. Or maybe dig into BEP archives or engraver's notes to see if there's some internal jargon at work.

Let me know how you'd like to go from here!

I actually think this is a fine use of AI technology. It was a conversation with the human researcher in charge, working with an eager but less-knowledgeable assistant. The assistant does the legwork, finding and pulling relevant bits from a vast library of resources. "Radial" is a fair description of the shape, three lines radiating from a center. It may not be found in a numismatic reference, but it's apt. Likewise, "spandrel" comes from the world of art and architecture.

We still don't have a definitive answer, but this is progress. Although it took additional prompting, the assistant noted that it couldn't find an answer in the numismatic references it checked. It probably didn't have access to Gene Hessler's book.

When I interviewed for my job with the early search engine Lycos, they asked me to describe how I use search. I told them I started by visualizing the internet page I was hoping to find. What words were on it? Which words would tell me it's NOT the page I'm looking for? After formulating my search query and getting results, I would sometimes refine my search based on the results. And I would look deeper than just the top-ranked results - sometimes what I was looking for was further down in the rankings. And if after repeating this I still couldn't find what I was looking for? Then it wasn't in the index - the search engine didn't contain the result. I got the job.

Remember where this query started - it was just an image with crudely drawn circles and a mention of paper money. The system figured out that relevant references included Friedberg and Haxby and that the circled doodads/ornaments/whatever were flanking a serial number. It described them as used on U.S. notes as an anti-counterfeiting measure to "bookend" the serial number to prevent alterations. That's impressive. My wife or any other random non-numismatist would be flummoxed with that image and question.

None of this was possible with earlier versions of search and artificial intelligence. It didn't find a name for the doodads in its references, but it did come up with a fine candidate for a name. -Editor

Lee Lofthus found a hint in numismatic literature. -Editor

And here's what Michael Rocco found online. -Editor

Wow, that's perfect. Here's an excerpt. -Editor

Serials on the earliest large-size notes were simple numbers, with no letters or symbols around them. By 1869, however, serials were given a letter (or rarely, symbol) prefix and a symbol suffix as a security measure, to prevent alteration of the serials by adding digits. The letter prefix also allowed for a larger number of different serials to be printed, as the letter could be changed periodically to create new serial number blocks.

As the volume of currency issued increased, printings eventually became so large that an entire alphabet of prefix letters was not sufficient to give enough distinct serials for all the notes. Thus, letter suffixes began to be used as well, in place of symbol suffixes. The first use of a letter suffix was on 1882 $5 Nationals in 1899. After about 1913 the use of a letter as suffix became standard on new series, though some older series that remained in production continued to use symbol suffixes through the end of the large-size era.

The site's webmaster (if not the page's author) did use a different name for each of the symbol images. The three shown above were called "sprig", "pheon" and "triad", respectively. So the one in our original image is the "triad symbol". The web page also pictures the symbol Lee Loftus found, and this author also calls it a "brace", so at least we have some agreement there.

Thanks, everyone! Great topic. -Editor