You are skilled at wearing light armour.

Benefit: When you wear a type of armour with which you are proficient, the armour check penalty for that armour applies only to Dexterity and Strength-based skill checks. Additionally, you can cast spells while wearing light armour.

Normal: A character who is wearing armour with which he is not proficient applies its armour check penalty to attack rolls and to all skill checks that involve moving, and is unable to cast spells.

Special: Some classes automatically grant Light Armour Proficiency as a bonus feat. Members of those classes need not select it.