The vaisyas and ksatriyas may also engage in this worship (of the salagrama-sila), but it is compulsory in the house of a brahmana

Expressions researched:
"The vaiśyas and kṣatriyas may also engage in this worship, but it is compulsory in the house of a brāhmaṇa"

Sri Caitanya-caritamrta

CC Madhya-lila

Among the followers of the Vedic way, the śālagrāma-śilā, the vigraha of Nārāyaṇa, is worshiped in the form of a stone ball. In India, every brāhmaṇa still worships the śālagrāma-śilā in his home. The vaiśyas and kṣatriyas may also engage in this worship, but it is compulsory in the house of a brāhmaṇa.

CC Madhya 15.204, Translation and Purport

On the southern side of the kitchen were two rooms for offering food, and in one of them the food was offered to Śālagrāma Nārāyaṇa.

Among the followers of the Vedic way, the śālagrāma-śilā, the vigraha of Nārāyaṇa, is worshiped in the form of a stone ball. In India, every brāhmaṇa still worships the śālagrāma-śilā in his home. The vaiśyas and kṣatriyas may also engage in this worship, but it is compulsory in the house of a brāhmaṇa.