Lexmark C752 Technical Reference page 300

The value of this operator adds the extension .data to all filenames referenced when
using PostScript emulation file operators. To prevent the .data extension from being
added, issue the following PostScript emulation command:
statusdict begin
false setfilenameextend
end
To add the .data extension automatically again, issue:
statusdict begin
true setfilenameextend
end
The following example shows how to remove a file for the font myfont from the disk.
The PostScript emulation resource collection filename is
PostScript emulation command to remove the file is:
statusdict begin
false setfilenameextend
(%disk%myfont.type1) deletefile
true setfilenameextend
end
For other file types, see page 6-6.
Note: We recommend that you enable setfilenameextend as soon as possible
after you disable it. For example, the following PostScript emulation
commands generate an undefinedfilename error:
(%disk%iconimage) (w) file dup
(0f0606060686c6ff) writestring closefile
statusdict begin
false setfilenameextend
end
(%disk%iconimage) (r) file
%%[ Error: undefinedfilename; OffendingCommand: file ]%%
This occurs because the filename actually written to disk is iconimage.data. When
setfilenameextend is enabled (the default), all PostScript emulation file operators
treat filename operands as filename.data; when disabled, they treat filename
operands literally.
If you receive unexpected undefinedfilename or similar errors, try toggling
setfilenameextend and sending your print job again.
6-11
Memory
. The