Tamil is a Unicode block containing characters for the Tamil, and Saurashtra languages of Tamil Nadu India, Sri Lanka, Singapore, and Malaysia. In its original incarnation, the code points U+0B82..U+0BCD were a direct copy of the Tamil characters A2-ED from the 1988 ISCII standard. The Devanagari, Bengali, Gurmukhi, Gujarati, Oriya, Telugu, Kannada, and Malayalam blocks were similarly all based on their ISCII encodings.
Moore, Lisa (2001-11-06), "Motion 88-M9", Minutes from the UTC/L2 meeting #88, The UTC approves changing the general category type of U+0B83 TAMIL SIGN VISARGA from Mn to Lo.
Anderson, Deborah; Whistler, Ken; Pournader, Roozbeh; Moore, Lisa; Liang, Hai; Cook, Richard (2018-01-19), "ScriptExtensions.txt changes for Indic", Recommendations to UTC #154 January 2018 on Script Proposals
Moore, Lisa (2018-03-19), "Action item 154-A120", UTC #154 Minutes, Make script extension changes in version 11.0 as documented in section 6B, pages 6-9 of L2/18-039.