LibreOffice writers has a limited line bookmark feature called reminders (access and set them through Navigator window).
Make reminders mimic how line bookmarks work in coding text editors.
1. One hotkey and button to set/unset a reminder at the current curser location
2. two hotkeys and buttons to navigate to next/previous reminder
3. colorize reminder locations, either by coloring the whole line or by a color blob in the left margin at that location.
Sounds like a fine request - marking as NEW.
Any suggestions as to what hotkeys we would use that wouldn't conflict with other hotkeys (both within LibreOffice and within the system itself)?
Alt+S (or Alt+Return, see below) to set/unset current position as a reminder
Alt+PgUp/PgDn to jump to prev/next reminder position in document (if at last reminder PgDn could cycle around to the first one)
Those hotkeys are not used by default on LibreOffice Writer install AFAICT. The hotkeys appear to have no system function in Windows either. I can't say for Linux systems.
One worry is that Alt+letter in some applications is a shortcut to open menus. In english LibreOffice Write no menu entry has Alt+S as hotkey but maybe some translations has that menu shortcut? An alternativ to Alt+S could be Alt+Return. One advantage with Alt+S is that it is easy to set with one hand.
If anyone reading this is unfamiliar with line bookmarks that can be jumped between the try Notepad++ or some similar coding text editor if you wish to see how the feature works. Several of them use ctrl+F2 to set the bookmark and F2 to jump to the next bookmark. (Those hotkeys are taken in Writer already.)
One example of where quick jump between reminders can be useful is when editing back and forth between two sections that are far apart in a long text document.
addition: Even if some LibreOffice Writer non english language version uses Alt+S as shortcut for one of the menus the user could, even if Alt+S was taken over for Reminder, access that menu by first pressing (and releasing) Alt and then pressing S.