There is sometimes a confusion as to why Gursikhs read Rehraas Sahib of different lengths. The last thing the Panth should be divided on is Gurbani, whether it is in Mool Mantar or Rehraas. Far too many youth who just have devotion to read more Bani are being misled to think that only a particular version of Rehraas Sahib is acceptable or right. There was a time when everyone read the same Rehraas. Overtime Gursikhs attached extra shabads as part of their own abhyaas (practice). If these Gursikhs were prominent, then when they passed away, their followers made their routine an inadvertent maryada (tradition).
In the early 20th century, the Panth came together on what is the basic Rehraas for the panth to follow. The Rehraas included in Sri Guru Granth Sahib was used a base and Chaupai Sahib (along with a Svaiya and Dohra), six-pauree Anand Sahib and Mundavni were also added. Rehraas Sahib is a dynamic bani and its length can be flexible but no one should doubt that any reading of Rehraas equal to or above what is prescribed by the panth is acceptable for a Sikh to read. Gursikhs are free to add Bani to the Rehraas Sahib decided upon by the panth if they wish to do so as a part of their personal preferences. However, all Gursikhs should respect the Panthic Rehraas and should not claim that only a particular longer version of Rehraas Sahib is acceptable or correct as doing so is harmful to panthic unity (togetherness).