A sub-tpye of Nāma (body-making) Karma, due to the Udaya (rise) of which a Jīva (soul) becomes Tīrthankara (ford-founder)the founder of the Tirtha (ford (to cross the ocean of mundane existence)).
Tīrthakaratvanirvartakaṃ tīrthakaranāma.
(TaBhā 8.12)