groff: ms Multiple Columns
4.3.6.3 Multiple columns
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The 'ms' macros can set text in as many columns as do reasonably fit on
the page. The following macros are available; all of them force a page
break if a multi-column mode is already set. However, if the current
mode is single-column, starting a multi-column mode does _not_ force a
page break.
-- Macro: .1C
Single-column mode.
-- Macro: .2C
Two-column mode.
-- Macro: .MC [width [gutter]]
Multi-column mode. If you specify no arguments, it is equivalent
to the '2C' macro. Otherwise, WIDTH is the width of each column
and GUTTER is the space between columns. The 'MINGW' number
register controls the default gutter width.