Any Regualtions On Provident Funds?

Would like to ask if there are any statutory requirements regarding provident funds?

If YES, is there a mandatory requirement that they should be managed by government, fund managers or can it be managed internally, e.g welfare group?

What is the common practice in managing of provident funds? E.g do they manage it internally or the fund managers managed on their behalf?

Any info on this would be greatly appreciated.

Thanks!