groff: Man font macros
4.1.3 Macros to set fonts
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The standard font is roman; the default text size is 10 points. If
command-line option '-rS=N' is given, use N points as the default text
size.
-- Macro: .SM [text]
Set the text on the same line or the text on the next line in a
font that is one point size smaller than the default font.
-- Macro: .SB [text]
Set the text on the same line or the text on the next line in bold
face font, one point size smaller than the default font.
-- Macro: .BI text
Set its arguments alternately in bold face and italic, without a
space between the arguments. Thus,
.BI this "word and" that
produces "thisword andthat" with "this" and "that" in bold face,
and "word and" in italics.
-- Macro: .IB text
Set its arguments alternately in italic and bold face, without a
space between the arguments.
-- Macro: .RI text
Set its arguments alternately in roman and italic, without a space
between the arguments.
-- Macro: .IR text
Set its arguments alternately in italic and roman, without a space
between the arguments.
-- Macro: .BR text
Set its arguments alternately in bold face and roman, without a
space between the arguments.
-- Macro: .RB text
Set its arguments alternately in roman and bold face, without a
space between the arguments.
-- Macro: .B [text]
Set TEXT in bold face. If no text is present on the line where the
macro is called, then the text of the next line appears in bold
face.
-- Macro: .I [text]
Set TEXT in italic. If no text is present on the line where the
macro is called, then the text of the next line appears in italic.