Craft Epic Magic Arms and Armor( Epic Level Handbook, p. 52)
[Epic, Item Creation]
You can craft magic arms and armor of epic power.
You can craft magic arms and armor which exceed the normal limits for such items (as stated in the DUNGEON MASTER's Guide). For instance, you could craft a magic sword with an enhancement bonus of greater than +5, with a total effective enhancement bonus greater than +10, or that required prerequisite spells of higher than 9th level. See Chapter 4: Epic Magic Items for examples of epic magic arms and armor.