<Li> Aśvalāyana: Includes 212 verses, all of which are newer than the other Rigvedic hymns . </Li> <Li> Śaṅkhāyana: Very similar to Aśvalāyana </Li> <Li> Saisiriya: Mentioned in the Rigveda Pratisakhya . Very similar to Śākala, with a few additional verses; might have derived from or merged with it . </Li> <P> Writing appears in India around the 3rd century BC in the form of the Brāhmī script, but texts of the length of the Rigveda were likely not written down until much later, and the oldest extant manuscripts date to AD ~ 1040, discovered in Nepal . While written manuscripts were used for teaching in medieval times, they were written on birch bark or palm leaves, which decompose and therefore were routinely copied over the generations to help preserve the text . Some Rigveda commentaries may date from the second half of the first millennium AD . The hymns were thus composed and preserved by oral tradition for several millennia from the time of their composition until the redaction of the Rigveda, and the entire Rigveda was preserved in shakhas for another 2,500 years from the time of its redaction until the editio princeps by Rosen, Aufrecht and Max Müller . </P>

The word used for a potter in rigveda was