Attention, not luck, will prevent an audit

On St. Patrick's Day, we all claim a bit of the Emerald Isle. But it takes more than the legendary luck of the Irish to prevent a tax audit.

True, the IRS has most recently been focusing its examinations on higher income taxpayers.

And more business, both large and small, also are getting once overs, especially when it comes to how they classify workers.

So most of us don't have to worry that much about getting that dreaded letter from an auditor. Unless, of course, we do something that attracts an IRS examiner's eye.

One way the IRS decides whether to pull a return for a closer look is if it sticks out from the crowd. Yep, when it comes to taxes, it doesn't pay to be unique.

What's the DIF? The agency uses DIF, or Discrimination Information Function, to compare filings. Basically, your tax return is compared to a computer model and is given a DIF score rating the probability of inaccurate information on the return.

Returns with high DIF scores are pulled and reviewed by actual IRS employees to determine which ones have the greatest potential for yielding additional taxes and, of course, the associated interest and penalties.

While the IRS acknowledges that is has a DIF system and tweaks it now and then, it's a highly guarded secret as to what goes into the calculations. But over the years, it's become obvious that the IRS doesn't look kindly upon filers whose itemized deductions vary greatly from the claims of most other taxpayers in the same income bracket.

So with the April 15 filing deadline less than a month away and many of us scrambling to find as many tax cuts as we can, I wanted to share with you some numbers pulled together by the tax information and software company CCH.

The table below is based on IRS statistics for tax year 2007, the latest complete figures available when it was produced earlier this year. It shows the average amount of popular deductions claimed on Schedule A's that year in six income brackets.