MATERIALITY http://www.solutionmatrix.com/materiality-concept.html The materiality concept is the principle that trivial matters are to be disregarded in accounting, and all important matters are to be disclosed. Items that are large enough to matter are material items. The materiality concept is an established, recognized accounting convention

The materiality concept addresses omissions and misstatements in accounting reports and in business case analysis
In the US, the predominant approach to deciding what is material and what is not, is the view written in the GAAP (Generally Accepted Accounting principles) that items are material if they could individually or collectively influence the economic decisions of users, taken on the basis of financial statements

Abuses of the materiality concept are more likely to have serious legal consequences in accounting, than in business case analysis.
For accountants, GAAP and FASB have resisted putting precise quantitative value on the size of misstatement or omission that qualifies as an error in materiality. Nevertheless, in reaching judgment on specific cases, auditors and courts have utilized several "rules of thumb." * On an income statement, an omission or error greater than 5% of Profit (before tax), or greater than 0.5% of sales revenues is more likely to be considered "large enough to matter." * On a balance sheet, a questionable entry more than 0.3 to 0.5% of total assets or more than 1% of total equity, is more likely to be viewed suspiciously.
The final judgment on a suspected materiality abuse, however, will also consider factors besides the magnitude of the error. Auditors and courts will also condier 1. Motivation and intent behind the error
If the intent is to keep stock prices inappropriately high, inflate reported earnings, or inappropriately influence merger / acquisition