In scientific or official documents, you usually need to insert footnote. It is a small text addition in the bottom of page with a corresponding reference number in the main text. You can insert footnote in LibreOffice Writer by menu Insert > Footnote/Endnote.
Place your cursor where you want the footnote to be. Go to menu Insert > Footnote/Endnote. Let it be default then press OK.
Insert Manual Footnote
The common usage of footnote is numbered. But if you want, you can change the numbering to any character or just alphabets. You can do it by menu Insert > Footnote/Endnote > select Character and type the alphabet you want. I give A and B example. You can try it with another character by Choose button.
|Footnote Shortcut Key|