9-track tapes have reflective stickers placed on the non-data side  from the beginning of the tape and  from the end of the tape to facilitate signaling the hardware to prevent the tape from unwinding from the hubs. These reflective stickers establish the beginning-of-tape (BOT) and end-of-tape (EOT) marks.
9-track tapes use reflective stickers on their non-data side to mark the beginning and end of the tape for hardware, preventing it from unwinding from the hubs. These stickers are called BOT (beginning-of-tape) and EOT (end-of-tape).