Codes 1 to 4 only work during battle and are great for leveling-up very quickly! Don't combine these codes with other codes that modify the same item. And remember that the items won't do their normal function when the code is on. i.e. the Antidote won't cure poison with the code turned on(you will level-up instead)
1. EV1A-CAPR - When you use Magical Herbs, you will go up one level!

2. EV1A-CAP8 - When you use Healing Seeds, you will go up one level!

3. EV1A-CAR8 - When you use the Antidote, you will go up one level!

4. EV1A-CAS8 - When you use Fairy Powder, you will go up one level!

5. 973T-D926 - Sell the Wooden Sword for $49,151

6. 973T-D996 - Buy a Wooden Rod for $60 with the code turned off, then turn the code and sell it back for $49,151. Repeat as often as you want!

7. 971A-D97N - Buy a Medical Herb for $10 with the code turned off, then turn the code and sell it back for about $49,000. Repeat as often as you want!

8. AB1A-CAF6 - Healing Seed is free(instead of $200).

9. AB1A-CAGN - Healing Drop is free(instead of $300).

10. AB1A-CAG6 - Antidote is free(instead of $20).

11. AB1A-CAH6 - Fairy Powder is free(instead of $100).

With codes 12 to 17 you may have to unequip, and then equip, the weapon before the change show. Keep in mind that the codes below will also affect any enemy that uses that weapon as well.
12. FK3T-CNBA - Makes the Wooden Sword much stronger!(42 ATT instead of only 3).

13. FK3A-CNCA - Makes the Short Sword much stronger!(42 ATT instead of only 5).

14. FK3T-CNBT - Makes the Short Spear much stronger!(42 ATT instead of only 6).

15. FK2A-CNGA - Makes the Short Axe much stronger!(42 ATT instead of only 5).

16. FK4A-CNAA - Makes the Wooden Rod much stronger!(42 ATT instead of only 3).

17. FK4T-CNBA - Makes the Short Knife much stronger!(42 ATT instead of only 5).

Codes 18 to 35 will let any character(even non-magic users) cast the spells shown, as long you have the weapon. Keep in mind that the weapon may be damaged in battle. The weapon doesn't have to be equipped for the codes to work, but you can only use one code for each weapon.
18. VP3T-CZA8 - The Wooden Sword casts a blaze 3 spell when used as an item in battle.

19. 3Z3T-CZA8 - The Wooden Sword casts a bolt 4 spell when used as an item in battle.

20. 2F3T-CZA8 - The Wooden Sword casts a aura 4 spell when used as an item in battle(everyone's HP will be fully restored!!).

21. 3V3A-CZB8 - The Short Sword casts a freeze 4 spell when used as an item in battle.

22. 3Z3A-CZB8 - The Short Sword casts a bolt 4 spell when used as an item in battle.

23. 2F3A-CZB8 - The Short Sword casts a aura 4 spell when used as an item in battle(everyone's HP will be fully restored!!).

24. 3V3T-CZBR - The Short Spear casts a freeze 4 spell when used as an item in battle.

25. 3Z3T-CZBR - The Short Spear casts a bolt 4 spell when used as an item in battle.

26. 2F3T-CZBR - The Short Spear casts a aura 4 spell when used as an item in battle(everyone's HP will be fully restored!!).

27. 3V2A-CZF8 - The Short Axe casts a freeze 4 spell when used as an item in battle.

28. 3Z2A-CZF8 - The Short Axe casts a bolt 4 spell when used as an item in battle.

29. 2F2A-CZF8 - The Short Axe casts a aura 4 spell when used as an item in battle(everyone's HP will be fully restored!!).

30. 3V3T-CZH8 - The Wooden Rod casts a freeze 4 spell when used as an item in battle.

31. 3Z3T-CZH8 - The Wooden Rod casts a bolt 4 spell when used as an item in battle.

32. 2F3T-CZH8 - The Wooden Rod casts a aura 4 spell when used as an item in battle(everyone's HP will be fully restored!!).

33. 3V4T-CZA8 - The Short Knife casts a freeze 4 spell when used as an item in battle.

34. 3Z4T-CZA8 - The Short Knife casts a bolt 4 spell when used as an item in battle.

35. 2F4T-CZA8 - The Short Knife casts a aura 4 spell when used as an item in battle(everyone's HP will be fully restored!!).

36. 2F1A-CTPR - Using medical herb heals all HP of party

37. 2F1A-CTP8 - Using healing seed heals all HP of party

38. 2F1A-CTRR - Using healing drop heals all HP of party

39. FK1A-CTR8 - Using Antidote restores all MP of party

40 FK1A-CTS8 - Using Fairy Powder restores all MP of party