• Any hole greater than 5/8th requires disclosure

• Multiple holes (regardless of size) require disclosure

• Single holes less than ¼” do not require disclosure

• A disclosure for holes between ¼” and 5/8” are made by the auction inspector
  based on the affected substrate (corrosion, damage to the substrate) and
  location (close to striker etc).

A good rule of thumb is anything larger than a dime. See the guide below.