Libx CommonMark Basics and Leaf Blocks

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    4Leaf blocks

    This section describes the different kinds of leaf block that make up a Markdown document.

    4.1Thematic breaks

    A line consisting of optionally up to three spaces of indentation, followed by a sequence of three or more matching -, _, or * characters, each followed optionally by any number of spaces or tabs, forms a thematic break.

    Example 43 
    ***
---
___

    <hr />
<hr />
<hr />

    Wrong characters:

    Example 44 
    +++

    <p>+++</p>
    Example 45 
    ===

    <p>===</p>

    Not enough characters:

    Example 46 
    --
**
__

    <p>--
**
__</p>

    Up to three spaces of indentation are allowed:

    Example 47 
     ***
  ***
   ***

    <hr />
<hr />
<hr />

    Four spaces of indentation is too many:

    Example 48 
        ***

    <pre><code>***
</code></pre>
    Example 49 
    Foo
    ***

    <p>Foo
***</p>

    More than three characters may be used:

    Example 50 
    _____________________________________

    <hr />

    Spaces and tabs are allowed between the characters:

    Example 51 
     - - -

    <hr />
    Example 52 
     **  * ** * ** * **

    <hr />
    Example 53 
    -     -      -      -

    <hr />

    Spaces and tabs are allowed at the end:

    Example 54 
    - - - -    

    <hr />

    However, no other characters may occur in the line:

    Example 55 
    _ _ _ _ a

a------

---a---

    <p>_ _ _ _ a</p>
<p>a------</p>
<p>---a---</p>

    It is required that all of the characters other than spaces or tabs be the same. So, this is not a thematic break:

    Example 56 
     *-*

    <p><em>-</em></p>

    Thematic breaks do not need blank lines before or after:

    Example 57 
    - foo
***
- bar

    <ul>
<li>foo</li>
</ul>
<hr />
<ul>
<li>bar</li>
</ul>

    Thematic breaks can interrupt a paragraph:

    Example 58 
    Foo
***
bar

    <p>Foo</p>
<hr />
<p>bar</p>

    If a line of dashes that meets the above conditions for being a thematic break could also be interpreted as the underline of a setext heading, the interpretation as a setext heading takes precedence. Thus, for example, this is a setext heading, not a paragraph followed by a thematic break:

    Example 59 
    Foo
---
bar

    <h2>Foo</h2>
<p>bar</p>

    When both a thematic break and a list item are possible interpretations of a line, the thematic break takes precedence:

    Example 60 
    * Foo
* * *
* Bar

    <ul>
<li>Foo</li>
</ul>
<hr />
<ul>
<li>Bar</li>
</ul>

    If you want a thematic break in a list item, use a different bullet:

    Example 61 
    - Foo
- * * *

    <ul>
<li>Foo</li>
<li>
<hr />
</li>
</ul>