<Li> Non-qualified stock options (NQSOs or NSOs) </Li> <Li> In the UK, there are various approved tax and employee share schemes, including Enterprise Management Incentives (EMIs). (Employee share schemes that aren't approved by the UK government don't have the same tax advantages .) </Li> <P> As of 2006, the International Accounting Standards Board (IASB) and the Financial Accounting Standards Board (FASB) agree that the fair value at the grant date should be estimated using an option pricing model . Via requisite modifications, the valuation should incorporate the features described above . Note that, having incorporated these, the value of the ESO will typically "be much less than Black--Scholes prices for corresponding market - traded options ..." Here, in discussing the valuation, FAS 123 Revised (A15) - which does not prescribe a specific valuation model - states that: </P> <P> a lattice model can be designed to accommodate dynamic assumptions of expected volatility and dividends over the option's contractual term, and estimates of expected option exercise patterns during the option's contractual term, including the effect of blackout periods . Therefore, the design of a lattice model more fully reflects the substantive characteristics of a particular employee share option or similar instrument . Nevertheless, both a lattice model and the Black--Scholes--Merton formula, as well as other valuation techniques that meet the requirements...can provide a fair value estimate that is consistent with the measurement objective and fair - value - based method.... </P>

The time period in which a change can be implemented is known as what option below ​