Ayurveda doctors and traditional vaids write ‘cheta’ before beginning prescription. It is written to assure long of the patients. There is an interesting story regarding ayurveda physicians writing ‘cheta’.
An interesting story is told about the legendary Hindu physician Dhanwantri. When he died, his disciples wanted to hold his Shradh. He had told them not to do so, but to eat his flesh so that they could become like him.
As the disciples were preparing for that, Yama, the god of death appeared, and, fearing losing their souls, forbade them from eating the body. He cunningly told them to throw away the flesh that they had already cut out.
This, the disciples did, and three other living beings ate it: the ants, the crows, and a woman from the so-called cobbler caste, named Cheta. All three were blessed with longevity. Some say it was not the crows. Hence, the practice of feeding crows at Shradh time, when the souls of ancestors are said to visit homes as crows. Incidentally, even today, Vaids begin their prescription with the word “Cheta” to assure long life for their patients.