The Miscellaneous branch under Configuration - File Handling has the following options:
Change file attribute when toggling read-only for active file
This setting instructs the editor to change the read-only status of the file when the command for read-only is toggled. The default setting (unchecked) allows the user to change the editor's state preventing or allowing modification of the file but causes no change to the actual file status when the read-only status is changed from ribbon/menu.
Lock file for write while editing
This setting causes the editor to keep the lock on any file that is opened. Additionally, if the file is already locked, it allows for open by read-only in this case prompting the user with a dialog box to confirm the open as read-only. This feature prevents modification of a file from outside of the edit session preventing loss of changes made.
Close all files when opening or switching projects
If this option is selected, all currently open files will be closed without a warning prompt when opening, closing, or switching projects. If this is not selected the user will be prompted as to whether or not the open files should be closed.
Create new file if file specified on command line does not exist
This setting instructs the editor to create a new file if the file specified to be opened on the command line does not exist. The default setting is to create the new file.
Create new Edit file when opening with no other files
This setting instructs the editor to create a new empty document (EDIT1) file when it starts up if no other files are being opened.