I thought I knew what a bookend note was. But I'm not so sure anymore. What is PMG referring to here?
It goes to show how you could get any attribution you want put on a label. It's a bit of a stretch for a bookend as it usually occurs with three of the leading and ending digits of the SN, but this note has repeating "31" in the first half of the SN and again in the second half of the SN. I believe the designation is just an option you select on the submission form to get it noted on the label, not something the TPG does for you automatically, so the customer, and any potential buyer, gets to decide if the note is worthy of that designation and hence worthy of any premium because of it thereafter.
Not sure if this member is still posting to CT or not but Clay Irving has a nice description of how bookends can also appear across more than one note, which could also explain the note in question if it came from a sequence. Scroll down to "bookend".
I think Krispy's second post got it right. When this note was originally certified, it was probably part of a consecutive group in which the next note had an error of some kind. Some error collectors like to get the "bookends" to an error--the perfectly normal notes right before and after the error note. Other collectors don't much care. We're probably looking at what happens when a collector of the latter type buys the error and dumps the bookends back on the market: we end up with a perfectly normal note in a holder that appears to imply it's special.
I think you guys are right about it being a "bookend" to an error. The note I posted is a part of a two note set. One error and the consecutive note. The other bookend is missing.
I'm still here! The "bookend" description and example is found in my glossary: http://www.panix.com/~clay/currency/glossary.html
These guys are right, bookends are just like they sound. I think bookends are great if you are going to display an error note, or sometimes a changeover note. But mainly an error note, a strong inversion, something like that, when you see the consecutive serials with the error in the middle, it's a really cool display. As a collector I'd almost never part with them, simply because the bookends themselves are normally of typical collector value, and even if I didn't want them, the guy I sell the important note too just might, and WILL pay a premium for the bookends if he does. Otherwise, the bookend notes on their own are strict market value. Never sell your bookends, unless you need food money...