Mac OS X Panther in a Nutshell, 2nd Edition

Name

file

Synopsis

                     f [filename]

Change the filename for the current buffer to filename. The next time the buffer is written, it will be written to file filename. When the name is changed, the buffer’s notedited flag is set, to indicate you aren’t editing an existing file. If the new filename is the same as a file that already exists on the disk, you need to use :w! to overwrite the existing file. When specifying a filename, the % character indicates the current filename. If no filename is specified, print the current name and status of the buffer.

Example

:f %.new