Hi,Everybody Good Day
Is there any possibility of preventing a product code being created again in otherwords prevent duplicating
No. You will have to enforce that manually.
How can this be enforced?
The way I do it is use batch update every so often and paste in Excel. There I will find duplicates and change them.
Similar ideas were suggested for transaction reference number duplicate detection and prevention, but I am not sure if inventory items are included.
No. However, you can find and merge duplicates. See the Guide: https://www.manager.io/guides/13606. Unfortunately, the program is currently working differently from what is described in the Guide. It currently searches only the item code, rather than item name. If that is intentional, it was never announced. If accidental, it would be a bug. I will research that.