Predefined Number Registers (UNIX in a Nutshell: System V Edition)

15.3. Predefined Number Registers

`$0`	Section depth
`$1`	First section number
`$2`	Second section number
`$3`	Third section number
`$4`	Fourth section number
`$5`	Fifth section number
`$6`	Sixth section number
`$V`	Relative vertical spacing in displays
`$c`	Current column number
`$d`	Delayed text number
`$f`	Footnote number
`$i`	Paragraph base indent
`$l`	Column width
`$m`	Number of columns in effect
`$p`	Numbered paragraph number
`$s`	Column indent
`$v`	Relative vertical spacing in text
`bi`	Display (block) indent
`bm`	Bottom title margin
`bs`	Display (block) pre/post spacing
`bt`	Block keep threshold
`ch`	Current chapter number
`df`	Display font
`es`	Equation pre/post space
`ff`	Footnote font
`fi`	Footnote indent (first line only)
`fm`	Footer margin
`fp`	Footnote point size
`fs`	Footnote prespace
`fu`	Footnote undent (from right margin)
`hm`	Header margin
`ii`	Indented paragraph indent
`pf`	Paragraph font
`pi`	Paragraph indent
`po`	Simulated page offset
`pp`	Paragraph point size
`ps`	Paragraph prespace
`qi`	Quote indent (also shortens line)
`qp`	Quote point size
`qs`	Quote pre/post space
`sf`	Section title font
`si`	Relative base indent per section depth
`so`	Additional section title offset
`sp`	Section title point size
`ss`	Section prespace
`tf`	Title font
`tm`	Top title margin
`tp`	Title point size
`xs`	Index entry prespace
`xu`	Index undent (from right margin)
`zs`	Floating keep pre/post space