UPDATE: What the IRS does on its website that's unfair to taxpayers
By Bill Bischoff
You can't rely on FAQs and other "unofficial" guidance posted on the IRS website
Taxpayers can't rely on Frequently Asked Questions (FAQs) and answers and other "unofficial" guidance that the IRS posts on its website at www.irs.gov (http://www.irs.gov), national taxpayer advocate Nina Olson recently explained in a blog post. While tax professionals already know about this issue, you may find it unsettling. Here's what you need to understand.
Tax guidance categories
IRS guidance comes in three basic categories.
Guidance in IRS final and temporary regulations is binding on both the IRS and taxpayers, except in relatively rare instances when a court is persuaded to invalidate a regulation. Some proposed regulations are also binding on the IRS and taxpayers. Regulations are subject to careful internal IRS review and public commentary before they are adopted. If you rely on guidance published in temporary and final regulations (and some proposed regulations), you cannot be assessed additional taxes or penalties for failing to "follow the rules."
Other official IRS guidance