Himitsu-kyo (Its correct name is Himitsu Fujo-kyo and it is the teaching which Shaka preached in order to give indefinite benefits separately (individually) to people whose patience is different while keeping the difference in teachings a secret (confidentially))
秘密教（ひみつ、正しくは秘密不定教といい、機根の違う衆生同士に説法の違いを知られず（秘密）に、各々別々（各別）に応じた不定の得益がある法を説いた教え）