Every change to a video or its page after publication is listed here, newest first.
A correction means we got something wrong. A source update means someone else revised their number after we used it, and the video was right when it was made. A retest means we ran the same test again on a new build.
On YouTube, a correction gets a "Correction:" line in the description and a pinned comment. A source update gets a pinned comment. The page shows the old and the new value side by side, with dates.
None so far.