CS-Star Notes.
CS-Star Notes are reproductions of Notes that have already been printed, but something has gone wrong with the printing process. I.e., a pallet falls over damaging the notes, ink is spilled over a bunch of notes, the machines tear or rip the notes, etc.
They are then destroyed, and new notes are printed. When these notes are reprinted, the suffix of the serial number is replaced with a “Star” or “*” to show that it is a reprint. By an act of Congress, there can only be one Note with the exact same serial numbers at any time. To this end, the notes are destroyed and then re-printed with a “*” where the last letter of the serial number would have been, indicating that it is a replacement note.

CS-Star Note Rarity.
For ease, efficiency, and cost-effectiveness, most CS-Star Notes are re-printed in batches of 3,600,000. This is the most common amount. However, some CS-Star Notes have been reprinted in batches as low as 8,000, making these very rare. The majority of CS-Star Notes are worth face value and others are worth thousands. With some research on auction sites, it is easy to determine value.

Note: This page contains excerpts and basic information from the book "The Green Guide to Fancy Serial Numbers". Please consider adding a copy to your library, thank you.