-In contrast to the other format letters, this one does not yet
-print the value and does not take an argument.
-Instead, the rest of the format string consists of pairs of
-argument type letters and style name letters.
-.El
-.Pp
-Argument type letters each require one argument as follows:
-.Bl -tag -width 1n -offset indent
-.It Cm h
-Requires one
-.Vt int
-argument, interpreted as a horizontal length in units of
-.Dv SCALE_EN .
-.It Cm s
-Requires one
-.Vt char *
-argument, used as a style value.
-.It Cm u
-Requires one
-.Vt struct roffsu *
-argument, used as a length.
-.It Cm w
-Requires one
-.Vt char *
-argument, interpreted as an
-.Xr mdoc 7 Ns -style
-width specifier.
-If the argument is
-.Dv NULL ,
-nothing is printed for this pair.
-.Pp
-The
-.Cm w
-argument type letter can optionally be followed by one, two, or three
-modifier letters.
-The modifier
-.Cm *
-suppresses printing of the pair if the argument matches 6n.
-The modifier
-.Cm +
-increases the width by 20% to make even bold text fit
-and adds three units for padding between columns.
-The modifier
-.Cm \-
-makes the width negative by multiplying it with \-1.
-.El
-.Pp
-Style name letters decide what to do with the preceding argument:
-.Bl -tag -width 1n -offset indent
-.It Cm h
-Set
-.Cm height
-to the given length.
-.It Cm i
-Set
-.Cm text-indent
-to the given length.
-.It Cm l
-Set
-.Cm margin-left
-to the given length.
-.It Cm w
-Set
-.Cm width
-to the given length.
-.It Cm W
-Set
-.Cm min-width
-to the given length.
-.It Cm \&?
-The special pair
-.Cm s?
-requires two
-.Vt char *