=over =item IO::Handle->output_field_separator( EXPR ) =item $OUTPUT_FIELD_SEPARATOR =item $OFS =item $, X<$,> X<$OFS> X<$OUTPUT_FIELD_SEPARATOR> The output field separator for the print operator. If defined, this value is printed between each of print's arguments. Default is C<undef>. You cannot call C<output_field_separator()> on a handle, only as a static method. See L<IO::Handle|IO::Handle>. Mnemonic: what is printed when there is a "," in your print statement. =back