S.N.D.P. means Sri Narayana Guru Dharma Paripalana Yogam or sangam.

It was founded by Narayana Guru.

More about S.N.D.P:

• Narayana Guru through his socio-religious teachings and writings has become much famous in the socioreligious and political scenario of Kerala during the 19th century.
• All the young people turned towards the reformative movements of Sri Narayana Guru.
• Also voluntarily they have redesignated their former youth association (it’s called Vivatu sangha) as S.N.D.P.
• It was registered as a joint-stock company in January 1903 with Sri Narayana Guru as a lifetime president.