Two explanations are attached to the second clause and they have had very different afterlives.
Explanation I provides that the wearing and carrying of kirpans shall be deemed to be included in the profession of the Sikh religion. It settles a practical question that most jurisdictions have had to answer some other way, and it is cited in comparative argument elsewhere for that reason.
Explanation II provides that the reference to Hindus in the clause about throwing open religious institutions shall be construed as including a reference to persons professing the Sikh, Jaina or Buddhist religion, and that references to Hindu religious institutions shall be construed accordingly. Its purpose in 1950 was to extend the temple entry power to the institutions of those traditions, so that caste exclusion could be reached wherever it operated.
The objection is that the drafting absorbs three traditions into a fourth. Sikh members of the Constituent Assembly objected at the time, and Sikh, Jain and Buddhist bodies have objected since, on the ground that a constitution which elsewhere names them as distinct religions here treats them as sections of Hinduism, and that the same construction runs through Indian personal law, where the Hindu Marriage Act and its companions apply to Sikhs, Jains and Buddhists by the same device.
The explanation has not been amended. The atlas records the provision and the objection, and does not resolve a question of constitutional interpretation.