In some cases, the staff allows dual calculations of tangible book value. For example, some intangible assets (such as patents) may be sold separately, but the ability to recover their carrying value may be indeterminable. Also, some material deferred costs are accounted for as adjustments to the yield on specific assets or liabilities (debt costs or policy acquisition costs). The staff has allowed tangible book value per share calculations made with and without those assets, with appropriate explanation.