Corrections and Updates

We keep a public record of corrections to factual errors and of significant updates to our guides. Small edits for clarity, spelling or formatting aren’t listed.

How to report an error

If you think a figure, rule or calculation on this site is wrong, please contact us with the page address, what you think is wrong and, if possible, a source. We review every report. If we confirm an error, we fix it, update the date on the guide and record it here.

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