text: **Income and Other Taxes**
  We make income and other tax provisions based on information 
  currently available in each of the jurisdictions in which we operate. 
  While we believe we have paid and provided for adequate amounts of 
  tax, our business is complex and significant judgement is required in 
  interpreting tax legislation and regulations and estimating future levels 
  of taxable income. Our tax filings are subject to audit by the relevant 
  government revenue authorities and the results of the government 
  audit could materially change the amount of our actual 
  income tax 
  expense, income taxes payable or receivable, other taxes payable or 
  receivable and deferred income tax assets and liabilities and could, in 
  certain circumstances, result in the assessment of interest and penalties. 
  
  *Restricted Share Unit (RSU) Plan*
  We record outstanding RSUs as liabilities, measuring our liabilities and 
  compensation costs based on the award’s fair value, and recording it as 
  a charge to operating costs over the vesting period of the award. If the 
  award’s fair value changes after it has been granted and before the 
  settlement date, we record the resulting changes in the liability as a 
  charge to operating costs in the year that the change occurs. The 
  payment amount is established as of the vesting date. 
  
  *Deferred Share Unit (DSU) Plan*
  We record outstanding DSUs as liabilities, measuring our liabilities and 
  compensation costs based on the awards’ fair values at the grant date. 
  If an award’s fair value changes after it has been granted and before 
  the settlement date, we record the resulting changes in our liability as a 
  charge to operating costs in the year that the change occurs. The 
  payment amount is established as of the exercise date. 
  
  **Pension Benefits**
  When we account for defined benefit pension plans, assumptions are 
  made in determining the valuation of benefit obligations. Assumptions 
  and estimates include the discount rate, the rate of compensation 
  increase and the mortality rate. Changes to these primary assumptions 
  and estimates would affect the pension expense, pension asset and 
  liability and other comprehensive income. Changes 
  in economic 
  conditions may also have an impact on our pension plan because there is 
  no assurance that the plan will be able to earn the assumed rate of 
  return. Market-driven changes may also result in changes in the discount 
  rates and other variables that would require us to make contributions in 
  the future that differ significantly from the current contributions and 
  assumptions incorporated into the actuarial valuation process. 