Deferred Executive Compensation - including charges related to any contingent obligation pursuant to an executive severance agreement, because we believe the period over which the obligation is amortized may not reflect the period of benefit and that such expense has no direct correlation with our recurring business operations and including such expenses does not accurately reflect the compensation expense for the period in which incurred.
Certain Income Tax Items - including certain deferred tax charges and benefits that do not result in a current tax payment or tax refund and other adjustments, including but not limited to, items unrelated to the current fiscal year or that are not indicative of our ongoing business operations.
The non-GAAP financial measures presented in the table above should not be considered in isolation and are not an alternative for the respective GAAP financial measure that is most directly comparable to each such non-GAAP financial measure. Investors are cautioned against placing undue reliance on these non-GAAP financial measures and are urged to review and consider carefully the adjustments made by management to the most directly comparable GAAP financial measures to arrive at these non-GAAP financial measures. Non-GAAP financial measures may have limited value as analytical tools because they may exclude certain expenses that some investors consider important in evaluating our operating performance or ongoing business performance. Further, non-GAAP financial measures are likely to have limited value for purposes of drawing comparisons between companies because different companies may calculate similarly titled non-GAAP financial measures in different ways because non-GAAP measures are not based on any comprehensive set of accounting rules or principles.
Our earnings release contains forward-looking estimates of non-GAAP gross margin, non-GAAP operating margin and non-GAAP diluted earnings per share for the fourth quarter of our 2015 fiscal year ("Q4 2015"). We provide these non-GAAP measures to investors on a prospective basis for the same reasons (set forth above) that we provide them to investors on a historical basis.
The following table provides a reconciliation of our forward-looking estimate of non-GAAP gross margin to a forward-looking estimate of GAAP gross margin for Q4 2015:
|Forward-looking non-GAAP gross margin estimate||50.0||%|
|Less: Share-based compensation expense||(0.5||)|
|Forward-looking GAAP gross margin estimate||49.5||%|