The -m option states that the input and output table data will contain special records
that marks the start of new line segments. These records are identified by their first
character, which can be specified as an argument to -m [The default is ].
Append the modifiers i or o if the option should only apply to input or output,
respectively. For binary data a multiple segment header is identified as a data record
where all fields equal NaN. See section 4.4.14 and Appendix B for more details.