Like her, I took a tax course in law school, and loved it (much to my surprise). Now I help folks with CRA disputes, occasionally taking them as high as the SCC.
I see Kelly's already up to the letter "R" for an April 15th tax filing deadline in the U.S., whereas I'm stuck with the letter "A" for an April 30th deadline in Canada. I've clearly got some catching up to do!
Today, A is for Amortization. You've probably heard about amortization when it comes to paying down your mortgage, but you might not have thought about it as a tax concept.
You generally "depreciate" significant tangible property you purchase to earn income, like a vehicle or a building. The Income Tax Act refers to this as Capital Cost Allowance, and specifies a variety of rates depending on the type of property.
For intangible property you acquire to earn income, like goodwill or intellectual property, you "amortize" it. The Income Tax Act calls this Eligible Capital Property, and again you can write it off at a certain percentage a year.
You "amortize" intangibles rather than "depreciate" them, because they in theory can have an indefinite life that never wears out (unlike that orange Volkswagen camper van painted with flowers that you used to use in your outfitting business).
Generally Accepted Accounting Principles (GAAP) rules have recently changed so that goodwill is now treated somewhat differently than other intangibles for write down purposes, so that it's tested each year for impairment, rather than simply (yes, perhaps I'm overly stretching the meaning of the word "simply" here) "amortized." But you still amortize other intangibles like patents, as they'll eventually expire.
The concept to get here is that if you've purchased something for the purpose of earning income, then you're allowed to gradually deduct its cost as it wears out - even if its not a tangible thing. But since goodwill (and supposedly diamonds) is forever, you might not be able to deduct it unless you can show some proof of its diminishing in value.
A Frankfurt team of accountants has come up with with this cool (at least for those of us fond of tax concepts) comparison of tax amortization rates by country and type of intangible: http://www.taxamortisation.com.