What powers does Parliament possess with respect to varying or revoking the conditions of service of officers mentioned in Article 312A?
The power of Parliament to vary or revoke the conditions of service of officers mentioned in Article 312A is not explicitly mentioned within the given context. However, it can be inferred from the text that Parliament has the authority to create new all-India services and regulate the recruitment and conditions of service for persons appointed to these services under Article 312(1).