-if \f[I]OUTSPEC\f[] begins with a \f[I]-\f[] character, use the
-rest of OUTSPEC as the filename, but force overwrite any existing
-file by that name
+If \f[I]OUTSPEC\f[] begins with a \f[I]#\f[] character, parse the
+rest as a file descriptor number, and feed the data to this file
+descriptor.