This excerpt taken from the PNC 10-K filed Mar 2, 2009.
ESTIMATES AND JUDGMENTS
Our consolidated financial statements are prepared by applying certain accounting policies. Note 1 Accounting Policies in the Notes To Consolidated Financial Statements in Item 8 of this Report describes the most significant accounting policies that we use. Certain of these policies require us to make estimates and strategic or economic assumptions that may prove inaccurate or be subject to variations that may significantly affect our reported results and financial position for the period or in future periods.