Provident fund investment pattern rules set category limits, rating conditions, and trustee due diligence requirements. The investment pattern for Non-Government Provident Funds, Superannuation Funds and Gratuity Funds is modified with effect from 1 April 2015, setting category-wise limits for Government securities, debt instruments, short-term instruments, equities, and asset-backed or trust-structured investments. The framework prescribes minimum ratings, listing requirements, maturity conditions, banking prudential criteria, and sub-category caps, while also regulating fresh accretions, turnover ratio, exit on rating deterioration, arms-length investment, due diligence, trustee responsibility, and cost control in fund management.