gnucash/libgnucash/doc/tax.txt

/** \page taxnotes Some notes about taxes

From: Jon Kaare Hellan <Jon.K.Hellan@item.ntnu.no>

Norwegian rules are more or less as follows:

You pay income tax on 
(sale price - commission) - (adjusted purchase price + commission)

Adjusted purchase price?? That's what makes us different.

Each Jan. 1., the cost base of stocks you hold is adjusted by some
amount. How it is computed does not matter here, but the idea is that
once the company has paid tax on a profit, a corresponding amount of
capital gains becomes tax free to the stockholders. Theoretically
attractive, difficult in practice.

So I need a way to keep track of these adjustments register for each
stock in a portfolio.

*/