Article 370 of the Indian Constitution is a law that grants special autonomous status to Jammu and Kashmir.
Article 370 was worked out in late 1947 between National Conference leader Sheikh Abdullah, who had by then been appointed Prime Minister of J&K by Maharaja Hari Singh, and former Indian Prime Minister Pandit Jawahar Lal Nehru, who kept the Kashmir portfolio with himself and kept Sardar Patel, the then Home Minister, out of it.
This article specifies that except for Defence, Foreign Affairs, Finance and Communications (matters specified in the instrument of accession), the Indian Parliament needs the State Government's concurrence for applying all other laws.
Thus the state's residents lived under a separate set of laws, including those related to citizenship, ownership of property, and fundamental rights, as compared to other Indians.
The BJP has been demanding repeal of the provision with the party's prime ministerial candidate Narendra Modi recently claiming that both Congress and National Conference had 'misused' Article 370 to deprive the people of the state of their fundamental rights and promote communalism, separatism and politics of regional discrimination.
Modi said under Article 370 Jammu and Kashmir Chief Minister Omar Abdullah's sister, who is married to Congress leader Sachin Pilot, did not enjoy the same rights in the state as Omar did.
To this, Omar replied: 'He very conveniently used me and my sister as examples to illustrate a point that has no bearing in truth. Either he lies or is ill-informed.'
(With inputs from Wikipedia)