A technician performs an internal visual inspection on the inside of a cargo tank. Which marking letter code should be applied to the tank to document that specific inspection?

49 CFR 180.415(b)(3)

External and internal visual inspections (V and I) check different surfaces of the same tank and are logged with different codes. Mixing them up on an exam, or in the field, would misrepresent which parts of the tank have actually been checked for safety defects.