Web page doc bug
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I deleted the form because this is a doc bug on the web page, independent of app or os version. https://iterm2.com/documentation-menu-items.html under Menu Items says
Edit > Clear Buffer
Clears the last screenful of the terminal.
Edit > Clear Scrollback Buffer
Clears the entire terminal history.
This seems incorrect. Clear Buffer clears the entire terminal history, including what's visible. Clear Scrollback buffer clears everything before what's visible. I'm not sure what "last screenful" is supposed to mean, but it doesn't seem to be a good description of the behavior of either menu option.