This excerpt taken from the MRVL 10-K filed Apr 13, 2006.
SECTION 9. WITHHOLDING TAXES.
No stock certificates will be released to you unless you have made acceptable arrangements to pay withholding taxes that may be due as a result of this award or the vesting of the shares. With the Companys consent, these arrangements may include (a) withholding shares of Company stock that otherwise would be delivered to you when they vest or (b) surrendering shares that you previously acquired. The fair market value of the shares you surrender, determined as of the date when taxes otherwise would have been withheld in cash, will be applied as credit against the withholding taxes.