This excerpt taken from the EFX 10-K filed Feb 26, 2009.
A Participant shall be responsible for and indemnify all relevant Group Members against, all Relevant Tax relating to his exercise of the Option. Any Group Member may withhold an amount equal to such Relevant Tax from any amounts due to the Participant (to the extent such withholding is lawful) and/or make any other arrangements as it considers appropriate to ensure recovery of such Relevant Tax including, without limitation, the sale of sufficient Shares acquired pursuant to the exercise of the Option to realise an amount equal to the Relevant Tax (and the payment of that amount to the relevant authorities in satisfaction of the Relevant Tax).
This excerpt taken from the EFX DEF 14A filed Mar 28, 2008.
(a) Withholding. In the event the Company or an Affiliate of the Company is required to withhold any Federal, state or local taxes or other amounts in respect of any income recognized by a Participant as a result of the grant, vesting, payment or settlement of an Award or disposition of any Shares acquired under an Award, the Company may deduct (or require an Affiliate to deduct) from any payments of any kind otherwise due the Participant cash, or Shares otherwise deliverable or vesting under an Award, to satisfy such required tax withholding obligations. Alternatively, the Company may require such Participant to pay to the Company, in cash, promptly on demand, or make other arrangements satisfactory to the Company regarding the payment to the Company of the aggregate amount of any such taxes and other amounts. If Shares are deliverable upon exercise or payment of an Award, the Committee may provide in the Award agreement for the Participant to satisfy all or a portion of the Federal, state and local withholding tax obligations arising in connection with such Award by electing to: (a) have the Company withhold Shares otherwise issuable under the Award; (b) tender back Shares received in connection with such Award; or (c) deliver other previously owned Shares; provided that the amount to be withheld may not exceed the total minimum federal, state and local tax withholding obligations associated with the transaction to the extent needed for the Company to avoid an accounting charge. If an election is provided, the election must be made on or before the date as of which the amount of tax to be withheld is determined and otherwise as the Committee requires. In any case, the Company may defer making payment or delivery under any Award if any such tax may be pending unless and until indemnified to its satisfaction.
(b) No Guarantee of Tax Treatment. Notwithstanding any provisions of the Plan, the Company does not guarantee to any Participant or any other Person with an interest in an Award that: (i) any Award intended to be exempt from Code Section 409A shall be so exempt; (ii) any Award intended to comply with Code Section 409A or Code Section 422 shall so comply; and (iii) any Award shall otherwise receive a specific tax treatment under any other applicable tax law, nor in any such case will the Company or any Affiliate indemnify, defend or hold harmless any individual with respect to the tax consequences of any Award.