This invention relates to encoding methods using up-converting phosphors for high-throughput screening of catalysts. The stanchion supports a slide fixed vertically at any desired height in the stanchion by a locking member movable into a track in the slide. The shank includes an upper support tube, a lower sliding tube adapted to slide in the support tube, and a rotatable locking device fixedly provided on a top of the sliding tube. The spacing \u03c4 and pitch T of the patterns are determined by the following m value in the following formulae. The etchant includes about 3% to about 10% by weight of hydrofluoric acid and about 1% to about 5% by weight of hydrogen peroxide. Magnetic recording heads and disc drives that record data in accordance with the method are also included.