Rules Rules in IPRU (INS) showing how, for required minimum margin purposes, an insurer’s assets must be valued. Generally assets are valued at market value as prescribed in the rules but insurers must now apply the resilience test as a safeguard against changes in value of assets. Where an asset cannot be valued in a prescribed way it must be omitted from the margin of solvency calculation. The rules restrict the proportion of total assets held in any one asset or asset class. The assets eligible to cover solvency requirements comprise three groups: those that may be accepted without limitation; those subject to some limitation; and those acceptable only with FSA approval.