Conversion of indorsement limits liability: only the full indorsee or their successor may claim the full amount. When a negotiable instrument indorsed in blank is later indorsed in full, only the person to whom it has been indorsed in full or a transferee deriving title through that person may claim the full amount from the indorser in full; other holders who do not derive title through the full indorsee cannot enforce full-payment liability against that indorser.