Gotta love the cunning bastards that concocted the French on-line tax return. On page N you declare whatever salaries, pensions, etc. you've received throughout the previous year, and they've very helpfully filled it in for you with figures supplied by whoever paid you. If you have any doubts to make known, they've supplied a text box on page N+m wherein you may state them. Catch-21½: if to do this you need to refer to your earlier entries and press the "previous" button to refer to them, you get a warning that you'll lose what you typed, and a little note tells you not to paste text into the box because doing so may make the bloody thing hang.
I would like to take the genius who thought that one up out to dinner, and sprinkle his/her/its/their plate with strychnine when nobody's looking.