etymology: aindhi karyangal udaiyavan. (The one who performs the five tasks i.e.)
1. Add Dasa to the end of one's name.
2. Place 12 Srivaishhava marks on the body
3. Understand the three mantras
4. Learn how to do aradhana to the Lord
5. Wear the marks of the conch and wheel on ones shoulders.
See [Wikipedia] for additional details
See also: Brahmin Vaishnava