The 10 character limit is removed at the time of entering the discount coupon code.
The new length is 20 characters, which without modifying the database, is the maximum available.



Instrucctions:
Installation is through standard extension installer
1. Open Extensions -> Extension installer
2. Select module file *.ocmod.zip
3. Go to Extensions -> Modifications and press refresh button

To see the results, go to the BackOffice Coupon List and add/modify a coupon.