VLC HowTo/Save bookmarks
If you wish to save bookmarks this is how it can be done.
Set up the Bookmark list and then save a Playlist. Open the playlist dialog with menu selection View-Playlist. The playlist window has a menu selection Manage that allows opening and saving playlists.
Opening a saved playlist will also load an associated bookmark list.
Shortcut keys Ctrl-P (Open playlist) and Ctrl-B (Open Bookmarks) don't seem to work. In general, on my computer, some shortcuts work and some don't.
Although more bookmarks can be set up, there seems to be a limit to the number of bookmarks which can be saved in the playlist. Possibly, the limit is determined by the number of bytes the bookmark list takes up in the playlist (m3u) file. Therefore, shorter bookmark names equal more bookmarks. Also, the m3u file is a text file and can be edited. There is a bytes parameter which is not necessary if all you want to do is bookmark locations. (This information is tentative. Conclusions have not been exhaustively tested.)
The bookmark window's behavior is inconsistent. When loaded with the playlist, the only way it apparently will display is maximized. This is somewhat inconvenient because if the playlist (m3u) file format is associated with VLC, when you click on the m3u file, you can't view the bookmark list and VLC at the same time. You may get around this by opening VLC first, then opening the (empty) bookmark list. Then, when you load the desired playlist, the booklist can be accessed in an adjustable size.