troff -man file ...
Any text argument t may be zero to six words. Quotes may be used to include blanks in a `word'. If text is empty, the special treatment is applied to the next input line with text to be printed. In this way .I may be used to italicize a whole line, or .SM followed by .B to make small bold letters.
A prevailing indent distance is remembered between successive indented paragraphs, and is reset to default value upon reaching a non-indented paragraph. Default units for indents i are ens.
Type font and size are reset to default values before each paragraph, and after processing font and size setting macros.
These strings are predefined by -man:
ka
Request Cause If no Explanation Break Argument
t no t=n.t.l.* Text t is bold. t no t=n.t.l. Join words of t alternating bold and
italic. t no t=n.t.l. Join words of t alternating bold and Roman.
d.
Set prevailing indent to .5i. Set prevailing indent to amount of starting .RS. t no t=n.t.l. Join words of t alternating Roman and bold. t no t=n.t.l. Join words of t alternating Roman and italic.
move left margin in distance i. Set prevailing indent to .5i for nested indents.
* n.t.l. = next text line; p.i. = prevailing indent