You can treat all the exotic weapons associated with your race as martial weapons rather than as exotic weapons. A weapon is treated as being associated with a race if the race's name appears as part of the weapon's name, such as the elven thinblade (see Chapter 4 of this book) or the dwarven urgrosh.
Without this feat, you must select the Exotic Weapon Proficiency feat (or have the appropriate weapon familiarity as a racial trait) to eliminate the nonproficiency penalty you take when wielding an exotic weapon associated with your race.
