Auspicious marks, of sacred clay and other substances, applied daily on the forehead (and sometimes on various limbs as well) to dedicate one's body to God.
yellow clay from the holy rivers of India applied by the v a i s h n a v a s in the form of a tuning-fork with a leaf of t u l s i in clay on the nose and the forehead (and other places of the body) as a token of submission to the teaching.