Editions, ISBNs, pack sizes and stock you can trust: how book depots and stationers in Pakistan can keep their shelves and their records in agreement.
When a school changes the edition of a reader, the old and new copies are different stock at different prices. How BooksPOS keeps each edition as its own item, from import to the till to publisher returns.
Pencils come in boxes of 12, markers in boxes of 10, paper in reams of 500, and customers buy all of them loose too. How to set pack sizes per item so stock stays exact whichever way you sell.
The last character of every ISBN is worked out from the others. Here is how the ISBN-10 and ISBN-13 check digits are calculated, how the two forms convert, and why BooksPOS refuses a wrong ISBN instead of guessing.