You are well-trained in the use of particular sets of armor.
Prerequisites: BAB +1, proficiency with armor
Select one weight class of armor (light, medium, heavy) that you are proficient with. When wearing armor in that weight class, you gain another +1 armor bonus to your AC.
Special: You may take this feat multiple times. Its effects do not stack. Each time you take this feat, you apply it to a different weight class of armor.