(b)
The following table entitled GAAP to Non-GAAP Reconciliations presents the computations of certain financial measures related to tangible common equity and cash efficiency. The table reconciles the GAAP performance measures to the corresponding non-GAAP measures, which provides a basis for period-to-period comparisons.
(c)
(d)
December 31, 2020, ratio is estimated and reflects Key s election to adopt the CECL optional transition provision.
GAAP to Non-GAAP Reconciliations
(dollars in millions)
The table below presents certain non-GAAP financial measures related to tangible common equity, return on average tangible common equity, pre-provision net revenue, and cash efficiency ratio and certain ratios excluding notable items.
Notable items include certain revenue or expense items that may occur in a reporting period which management does not consider indicative of ongoing financial performance. Management believes it is useful to consider certain fina