A more thorough explanation:

The claim-of-right doctrine is a rule in tax law that requires any income that a taxpayer has constructively received to be reported as income, regardless of whether the taxpayer has an unrestricted claim to it.

For example, let's say that John works for a company that accidentally overpays him by $1,000. Even though John knows that the money is not rightfully his, he still cashes the check and spends the money. Under the claim-of-right doctrine, John must report the $1,000 as income on his tax return, even though he was not entitled to it.

Another example would be if a taxpayer receives money from an illegal activity, such as drug dealing. Even though the income is obtained illegally, it is still subject to taxation under the claim-of-right doctrine.

The claim-of-right doctrine is designed to ensure that taxpayers report all income that they have received, even if they do not have a legal right to it. This helps to prevent tax evasion and ensures that everyone pays their fair share of taxes.