11.5.2 Body headings

The body heading rules specify up to four characteristics.

Level: From 1 to 4, specifies the hierarchy level. Level 2 headings are subtopics of level 1 headings and so on. Table of contents uses the value of level for the indentation of the table of contents entry for a heading.
Heading: From 1 to 4, specifies the size of characters used to display the text. H1 is the largest. These correspond to the HTML tags H1, H2, H3, and H4.
HR: Specifies a horizontal rule below the text. Corresponds to HTML tag HR.
Node: Specifies a node rule for headers that produce a new node.

Table 11.1 Behavior of Body Heading Rules
Rule	Level	HTML	Horiz. Rule	New Node	Buttons
L1H1HR-NodeTop	1	<H1>	No	No	Next, Previous, Top
L1H1-NodeTop	1	<H1>	No	Yes	Next, Previous, Top
L2H1HR-NodeLower	2	<H1>	Yes	Yes	Next, Previous, Top, Up
L2H1-NodeLower	2	<H1>	No	Yes	Next, Previous, Top, Up
L2H2-NodeLower	2	<H2>	No	Yes	Next, Previous, Top, Up
L3H1HR-NodeLower	3	<H1>	Yes	Yes	Next, Previous, Top, Up
L3H1-NodeLower	3	<H1>	No	Yes	Next, Previous, Top, Up
L3H2-NodeLower	3	<H2>	No	Yes	Next, Previous, Top, Up
L3H3-NodeLower	3	<H3>	No	Yes	Next, Previous, Top, Up
L4H1HR-NodeLower	4	<H1>	Yes	Yes	Next, Previous, Top, Up
L4H1-NodeLower	4	<H1>	No	Yes	Next, Previous, Top, Up
L4H2-NodeLower	4	<H2>	No	Yes	Next, Previous, Top, Up
L4H3-NodeLower	4	<H3>	No	Yes	Next, Previous, Top, Up
L4H4-NodeLower	4	<H4>	No	Yes	Next, Previous, Top, Up
L1H1	1	<H1>	No	No
L1H1HR	1	<H1>	Yes	No
L2H1	2	<H1>	No	No
L2H1HR	2	<H1>	Yes	No
L2H2	2	<H2>	No	No
L2H2HR	2	<H2>	Yes	No
L3H1	3	<H1>	No	No
L3H1HR	3	<H1>	Yes	No
L3H2	3	<H2>	No	No
L3H2HR	3	<H2>	Yes	No
L3H3	3	<H3>	No	No
L3H3HR	3	<H3>	Yes	No
L4H1	4	<H1>	No	No
L4H1HR	4	<H1>	Yes	No
L4H2	4	<H2>	No	No
L4H2HR	4	<H2>	Yes	No
L4H3	4	<H3>	No	No
L4H3HR	4	<H3>	Yes	No
L4H4	4	<H4>	No	No
L4H4HR	4	<H4>	Yes	No