Sin (pāpa) and its expiation (prāya-ścitta) is one of the topics discussed by the dharmaśāstras, often in great detail. Many of the expiatory rites have been given the general name ‘kṛcchra’ (‘that which cuts happiness or causes suffering). Out of the several kṛcchras, the ‘ardha-kṛcchra’ is an expiation for minor sins and causes only ’half‘ the suffering of a kṛcchra (ardha = half).
The repentant transgressor is expec-ted to subsist on food obtained without asking for it, for the first three days and thereafter fast completely for three more days.
As per another rule, he should eat only once in a day for two days, subsist on food got unasked for two more days and fast completely for the last two days of the six day discipline.
See also KṚCCHRA.