Setting made in the Buffer Options dialog are lost after the file is closed. jEdit supports a "buffer-local" string embedded in individual files to restore those settings the next time the file is opened. Unfortunately, there isn't a nice gui to create the buffer-local line, and some coding standards prohibit putting such editor/ide specific lines directly into the source code. To get around this, the BufferLocal plugin stores the settings made using the Buffer Options dialog box and applies those settings to each file as they are opened. There is no set up or configuration for this plugin, once installed, it is active. Use the Buffer Option dialog to adjust the settings for a file, and those settings will automatically be saved and applied to the file the next time it is opened.