Inscribe Epic Runes( Player's Guide to Faerûn, p. 136)
You can inscribe runes of epic power.
You can inscribe runes that exceed the normal limits (see Runcaster prestige class). For instance, you could inscribe a rune with a spell greater than 9th level, or a rune with a caster level greater than 20th. Even this feat does not allow you to inscribe a rune with an epic spell (see Chapter 2: Epic Spells in the Epic Level Handbook). Such magic defi es the power of the written word and thus cannot be scribed into runic form.