Power-lifting
Your lifting and carrying capacity is out of proportion with the rest of your Strength. Each rank in this power gives you +1 to your Strength rank for determining how much weight you can lift and carry, but does not increase your Strength-based damage, strength checks (including skills) except for lifting, or other effects of your Strength rank.
Since this doesn't increase damage it is not limited by the "Effect rank of an Attack" limitation but is still limited by "Every other Skill Modifier" as described in power level limitations.