The Sikh Rehat Maryada committee looked at various sources when compiling the SRM. The document that was created sets out conditions for anyone who claims to be a Sikh. And one such condition is that he should faithfully believe in:
iv. The utterances and teachings of the ten Gurus
(SRM, Section 1, Article I)
So this means that belief in Sri Guru Granth Sahib and the Sri Dasam Granth is mandatory for every Sikh.
With regards to the recitation of Kirtan, SRM gives the following instructions:
In the congregation, Kirtan only of Gurbani (Guru Granth’s or Guru Gobind Singh’s
hymns) and, for its elaboration, of the compositions of Bhai Gurdas and Bhai Nand Lal,
may be performed.
(SRM, CHAPTER V, Article VI)
Also Sri Guru Granth Sahib, Sri Dasam Granth, Bhai Gurdas’ Vars and Kabitts and compositions of Bhai Nand Lal are sanctioned to be recited in all Gurudwaras. Additionally, the Nitnem of the Sikhs comes from Sri Guru Granth Sahib and various compositions of Sri Dasam Granth including Akal Ustat, Krishnavtar, Ramavtar, and Charitropakhyan etc. The first pauree of Ardas is from “Chandi Di Vaar” in Sri Dasam Granth. While preparing Khande De Pahul (Amrit), Banees from both the Sikh scriptures, Sri Guru Granth Sahib and Sri Dasam Granth are recited. Hence it is fallacy to state that “Dasam Granth was not used by SRM committee when they composed Sikh Rehat Maryada”.