the IRS does give a hoot about your W-4. The IRS does not get a copy. it is completed by you to give to your employer to calculate withholding. exemptions claimed can differ from what is done when the tax return is prepared. you sign the W-4 under penalties of perjury. its ok to claim fewer that what your entitled to.
if you claim too few, you'll probably get a refund. claim to many and you might owe and there might be a penalty for underpayment of tax.
claim exempt when your not or way more exemptions than what you really entitled to is when a problem could occur.
