In some parts of the state, there is a practice of serving food and beverages in separate tumblers for members of the Dalit and other castes.
The accused Arumugam Servai and Ajit Kumar, who belonged to the 'servai" bacward caste community, were convicted by the sessions judge Madurai for calling the Dalits Panneerselvam and Mahamani by their caste "pallan" and assaulting them.
"The word ‘pallan’ no doubt denotes a specific caste, but it is also a word used in a derogatory sense to insult someone (just as in North India the word ‘chamar’ denotes a specific caste but it is also used in a derogatory sense to insult someone).
"Even calling a person a ‘pallan’, if used with the intent to insult a member of the Scheduled Caste, is, in our opinion, an offence under Section 3(1)(x) of the Scheduled Castes and Scheduled Tribes (Prevention of Atrocities Act), 1989," Justice Katju writing the judgement said.
http://www.hindustantimes.com/Calling-Dalit-by-caste-an-offence-SC/Article1-687198.aspx