.brl files from Guvnor Repository examples are opened as read-only but it's possible to modified them via .brl file editor in JBT.
It's even possible to save modified file and everything looks correctly saved. But when file is reopened there are no changes saved.
It should not be possible to edit read-only .brl file.

1. deploy guvnor to server and start server
2. open guvnor perspective
3. add default guvnor repository connection using Guvnor Repositories view
4. right click on newly created Guvnor connection and open Guvnor Console
5. choose ok to empty login dialog and click yes to install Guvnor examples
6. open <Guvnor connection> > pacakges > mortages > CheckBoxDslRule.brl file from Guvnor Repositories view
7. add new free form drl to condition save button gets enabled file looks like modified
8. save file everything looks like file is saved
9. Reopen the file and changes are not saved