Currently: "Left margin Enter the amount of space to leave between the left edge of the page and the left edge of the header. Right margin Enter the amount of space to leave between the right edge of the page and the right edge of the header." "the left/right edge of the page" should read "from the left/right page margin"
https://cgit.freedesktop.org/libreoffice/help/commit/?id=50ae47d7856c77dd682d0e7007acc70ee34fb5b5