Provide receipts and other supporting information if the IRS asks, but what if you have memos and letters from tax advisers about whether you qualify for a deduction, audit risk or potential tax litigation?

FORBES: What To Give IRS In An Audit

So why not, instead of mithering about with thank you letters and access to the carpool lanes, simply give them an honour?

FORBES: The Dilbert Guide To Taxing The Rich

The oddest response, though, is if you write making an obvious point about an historical period or historical figure, you will get lots of letters and emails insisting that the obvious thing about the guy or his time is completely wrong.

BBC: A Point of View: Science, magic, and madness

Write letters, or make phone calls on behalf of an issue you care about.

WHITEHOUSE: President Obama at Michigan Commencement

"They tell you a lot more about Kallenbach than Gandhi and it was very important to acquire the letters, " said Mr Hasan.

BBC: India to display Kallenbach papers about Mahatma Gandhi