That is the “index” of the book.
The index number is a number that is set automatically, based on the highest index number that you have currently. So:
- If the highest index number in your database is an book with index #250, the next book you add will get #251. No matter how many books you have.
Why use the index field?
- People use the Index numbers for stuff like putting stickers with a number on their books (to easily locate them in their book room). Therefor, each Index number is only used Once
- When a number is deleted, the next added book will still increment on the last added book.
So for instance:
- If you have #s 1,2,3,4,5,6,7,8,9,10
- You delete #4
- The next book you add will automatically be #11. #4 will not return.
- If you manually change #11 to #4, the next book you add will be #12 - so you will be missing #11.
If you don’t use the index number
You can open the menu top left, then go to Settings, then disable “Show index” and be done with it.