Add bookmark... (command Bookmarks/Add bookmark...)
Choose this to add a bookmark to the bookmark list. The offset will be
interpreted as a different value dependent upon the Options/Offset
Mode setting. The offset of
the bookmark will be set to the current position initially. You
can also add a description for the bookmark that will also appear
in the menu. Bookmarks added in this way are automatically saved
into the loaded table if a table is loaded.