The Sikh Rehat Maryada is the code of conduct approved by the SGPC in 1945 after about fifteen years of committee work involving scholars and representatives of the different Sikh traditions.
It covers personal discipline, nitnem, gurdwara practice, the conduct of ceremonies, the amrit ceremony, and the definition of a Sikh.
It was an attempt to settle by agreement a set of questions that had been argued since the Singh Sabha: what may be done in a gurdwara, what a Sikh marriage is, what a funeral is, whether the Dasam Granth may be installed, whether idols may be present.
It largely succeeded and it is the operative standard everywhere. It is also thin on several points, deliberately, because agreement could not be reached, and those points are exactly where the disputes have continued.
Earlier rehatnamas, attributed to Bhai Nand Lal Ji, Bhai Chaupa Singh, Bhai Desa Singh and Bhai Daya Singh, are the eighteenth and nineteenth-century material it was built from. They disagree with each other and with the 1945 text on many particulars.
The draft was circulated to gurdwaras, sabhas and individuals for comment, revised, and put through the SGPC more than once. The process was deliberately slow, and the record of the objections raised at each stage is the fullest surviving account of what Sikhs were arguing about in the 1930s.
It runs to about thirty pages. A document that short, covering everything from what may be sung in a gurdwara to how a body is carried out of a house, is short because it stops at every place where the committee could not get past a disagreement.
It is the only agreed statement of Sikh practice, and where it is silent or where a takht's practice differs from it, the disagreements of the last eighty years have collected.