brennen
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text-markdown-discount


								.\"

								.Dd Dec 22, 2007

								.Dt MARKDOWN 7

								.Os MASTODON

								.Sh NAME

								.Nm Markdown

								.Nd The Markdown text formatting syntax

								.Sh DESCRIPTION

								.Ss Philosophy

								.Nm Markdown

								is intended to be as easy-to-read and easy-to-write as is feasible.

								.Pp

								Readability, however, is emphasized above all else. A Markdown-formatted

								document should be publishable as-is, as plain text, without looking

								like it's been marked up with tags or formatting instructions. While

								Markdown's syntax has been influenced by several existing text-to-HTML

								filters -- including

								.Em Setext ,

								.Em atx ,

								.Em Textile ,

								.Em reStructuredText ,

								.Em Grutatext ,

								and

								.Em EtText

								\-\- the single biggest source of

								inspiration for

								Markdown's

								syntax is the format of plain text email.

								.Pp

								To this end, Markdown's syntax is comprised entirely of punctuation

								characters, which punctuation characters have been carefully chosen so

								as to look like what they mean. E.g., asterisks around a word actually

								look like *emphasis*. Markdown lists look like, well, lists. Even

								blockquotes look like quoted passages of text, assuming you've ever

								used email.

								.Ss Inline HTML

								Markdown's syntax is intended for one purpose: to be used as a

								format for

								.Em writing

								for the web.

								.Pp

								.Nm

								is not a replacement for HTML, or even close to it. Its

								syntax is very small, corresponding only to a very small subset of

								HTML tags. The idea is

								.Em not

								to create a syntax that makes it easier

								to insert HTML tags. In my opinion, HTML tags are already easy to

								insert. The idea for Markdown is to make it easy to read, write, and

								edit prose. HTML is a

								.Em publishing

								format; Markdown is a

								.Em writing

								format. Thus, Markdown's formatting syntax only addresses issues that

								can be conveyed in plain text.

								.Pp

								For any markup that is not covered by Markdown's syntax, you simply

								use HTML itself. There's no need to preface it or delimit it to

								indicate that you're switching from Markdown to HTML; you just use

								the tags.

								.Pp

								The only restrictions are that block-level HTML elements -- e.g.

								.Li \<div> ,

								.Li \<table> ,

								.Li \<pre> ,

								.Li \<p> ,

								etc. -- must be separated from surrounding

								content by blank lines, and the start and end tags of the block should

								not be indented with tabs or spaces. Markdown is smart enough not

								to add extra (unwanted)

								.Li \<p>

								tags around HTML block-level tags.

								.Pp

								For example, to add an HTML table to a Markdown article:

								.Bd -literal -offset indent

								    This is a regular paragraph.


								    <table>

								        <tr>

								            <td>Foo</td>

								        </tr>

								    </table>


								    This is another regular paragraph.

								.Ed

								.Pp

								Note that Markdown formatting syntax is not processed within block-level

								HTML tags. E.g., you can't use Markdown-style

								.Li *emphasis*

								inside an HTML block.

								.Pp

								Span-level HTML tags -- e.g.

								.Li \<span> ,

								.Li \<cite> ,

								or

								.Li \<del>

								\-\- can be

								used anywhere in a Markdown paragraph, list item, or header. If you

								want, you can even use HTML tags instead of Markdown formatting; e.g. if

								you'd prefer to use HTML

								.Li \<a>

								or

								.Li \<img>

								tags instead of Markdown's

								link or image syntax, go right ahead.

								.Pp

								Unlike block-level HTML tags, Markdown syntax *is* processed within

								span-level tags.

								.Ss Automatic Escaping for Special Characters

								In HTML, there are two characters that demand special treatment: `<`

								and `&`. Left angle brackets are used to start tags; ampersands are

								used to denote HTML entities. If you want to use them as literal

								characters, you must escape them as entities, e.g. `&lt;`, and

								`&amp;`.

								.Pp

								Ampersands in particular are bedeviling for web writers. If you want to

								write about 'AT&T', you need to write '`AT&amp;T`'. You even need to

								escape ampersands within URLs. Thus, if you want to link to:

								.Bd -literal -offset indent

								    http://images.google.com/images?num=30&q=larry+bird

								.Ed

								.Pp

								you need to encode the URL as:

								.Bd -literal -offset indent

								    http://images.google.com/images?num=30&amp;q=larry+bird

								.Ed

								.Pp

								in your anchor tag `href` attribute. Needless to say, this is easy to

								forget, and is probably the single most common source of HTML validation

								errors in otherwise well-marked-up web sites.

								.Pp

								.Nm

								allows you to use these characters naturally, taking care of

								all the necessary escaping for you. If you use an ampersand as part of

								an HTML entity, it remains unchanged; otherwise it will be translated

								into `&amp;`.

								.Pp

								So, if you want to include a copyright symbol in your article, you can write:

								.Bd -literal -offset indent

								    &copy;

								.Ed

								.Pp

								and Markdown will leave it alone. But if you write:

								.Bd -literal -offset indent

								    AT&T

								.Ed

								.Pp

								.Nm

								will translate it to:

								.Bd -literal -offset indent

								    AT&amp;T

								.Ed

								.Pp

								Similarly, because Markdown supports inline HTML, if you use

								angle brackets as delimiters for HTML tags, Markdown will treat them as

								such. But if you write:

								.Bd -literal -offset indent

								    4 < 5

								.Ed

								.Pp

								.Nm

								will translate it to:

								.Bd -literal -offset indent

								    4 &lt; 5

								.Ed

								.Pp

								However, inside Markdown code spans and blocks, angle brackets and

								ampersands are *always* encoded automatically. This makes it easy to use

								Markdown to write about HTML code. (As opposed to raw HTML, which is a

								terrible format for writing about HTML syntax, because every single `<`

								and `&` in your example code needs to be escaped.)

								.Sh Block Elements

								.Ss Paragraphs and Line Breaks

								.Pp

								A paragraph is simply one or more consecutive lines of text, separated

								by one or more blank lines. (A blank line is any line that looks like a

								blank line -- a line containing nothing but spaces or tabs is considered

								blank.) Normal paragraphs should not be indented with spaces or tabs.

								.Pp

								The implication of the

								.Qq one or more consecutive lines of text

								rule is

								that Markdown supports

								.Qq hard-wrapped

								Dtext paragraphs. This differs

								significantly from most other text-to-HTML formatters (including Movable

								Type's

								.Qq Convert Line Breaks

								option) which translate every line break

								character in a paragraph into a `<br />` tag.

								.Pp

								When you *do* want to insert a `<br />` break tag using Markdown, you

								end a line with two or more spaces, then type return.

								.Pp

								Yes, this takes a tad more effort to create a `<br />`, but a simplistic

								"every line break is a `<br />`" rule wouldn't work for Markdown.

								Markdown's email-style

								.Sx  blockquoting

								 and multi-paragraph

								.Sx  list items

								work best -- and look better -- when you format them with hard breaks.

								.Ss Headers

								.Nm

								supports two styles of headers,

								.Em Setext

								and

								.Em atx .

								.Pp

								Setext-style headers are

								.Sq underlined

								using equal signs (for first-level

								headers) and dashes (for second-level headers). For example:

								.Bd -literal -offset indent

								    This is an H1

								    =============


								    This is an H2

								    -------------

								.Ed

								.Pp

								Any number of underlining `=`'s or `-`'s will work.

								.Pp

								Atx-style headers use 1-6 hash characters at the start of the line,

								corresponding to header levels 1-6. For example:

								.Bd -literal -offset indent

								    # This is an H1


								    ## This is an H2


								    ###### This is an H6

								.Ed

								.Pp

								Optionally, you may

								.Qq close

								atx-style headers. This is purely

								cosmetic -- you can use this if you think it looks better. The

								closing hashes don't even need to match the number of hashes

								used to open the header. (The number of opening hashes

								determines the header level.) :

								.Bd -literal -offset indent

								    # This is an H1 #


								    ## This is an H2 ##


								    ### This is an H3 ######

								.Ed

								.Pp

								.Ss Blockquotes

								.Nm

								uses email-style `>` characters for blockquoting. If you're

								familiar with quoting passages of text in an email message, then you

								know how to create a blockquote in Markdown. It looks best if you hard

								wrap the text and put a `>` before every line:

								.Bd -literal -offset indent

								    > This is a blockquote with two paragraphs. Lorem ipsum

								    > dolor sit amet, consectetuer adipiscing elit. Aliquam

								    > hendrerit mi posuere lectus. Vestibulum enim wisi,

								    > viverra nec, fringilla in, laoreet vitae, risus.

								    >

								    > Donec sit amet nisl. Aliquam semper ipsum sit amet

								    > velit. Suspendisse id sem consectetuer libero luctus

								    > adipiscing.

								.Ed

								.Pp

								.Nm

								allows you to be lazy and only put the `>` before the first

								line of a hard-wrapped paragraph:

								.Bd -literal -offset indent

								    > This is a blockquote with two paragraphs. Lorem ipsum

								    dolor sit amet, consectetuer adipiscing elit. Aliquam

								    hendrerit mi posuere lectus. Vestibulum enim wisi,

								    viverra nec, fringilla in, laoreet vitae, risus.


								    > Donec sit amet nisl. Aliquam semper ipsum sit amet

								     velit. Suspendisse id sem consectetuer libero luctus

								      adipiscing.

								.Ed

								.Pp

								Blockquotes can be nested (i.e. a blockquote-in-a-blockquote) by

								adding additional levels of `>`:

								.Bd -literal -offset indent

								    > This is the first level of quoting.

								    >

								    > > This is nested blockquote.

								    >

								    > Back to the first level.

								.Ed

								.Pp

								Blockquotes can contain other Markdown elements, including headers, lists,

								and code blocks:

								.Bd -literal -offset indent

									> ## This is a header.

									>

									> 1.   This is the first list item.

									> 2.   This is the second list item.

									>

									> Here's some example code:

									>

									>     return shell_exec("echo $input | $markdown_script");

								.Ed

								.Pp

								Any decent text editor should make email-style quoting easy. For

								example, with BBEdit, you can make a selection and choose Increase

								Quote Level from the Text menu.

								.Ss Lists

								.Nm

								supports ordered (numbered) and unordered (bulleted) lists.

								.Pp

								Unordered lists use asterisks, pluses, and hyphens -- interchangably

								\-- as list markers:

								.Bd -literal -offset indent

								    *   Red

								    *   Green

								    *   Blue

								.Ed

								.Pp

								is equivalent to:

								.Bd -literal -offset indent

								    +   Red

								    +   Green

								    +   Blue

								.Ed

								.Pp

								and:

								.Bd -literal -offset indent

								    -   Red

								    -   Green

								    -   Blue

								.Ed

								.Pp

								Ordered lists use numbers followed by periods:

								.Bd -literal -offset indent

								    1.  Bird

								    2.  McHale

								    3.  Parish

								.Ed

								.Pp

								It's important to note that the actual numbers you use to mark the

								list have no effect on the HTML output Markdown produces. The HTML

								Markdown produces from the above list is:

								.Bd -literal -offset indent

								    <ol>

								    <li>Bird</li>

								    <li>McHale</li>

								    <li>Parish</li>

								    </ol>

								.Ed

								.Pp

								If you instead wrote the list in Markdown like this:

								.Bd -literal -offset indent

								    1.  Bird

								    1.  McHale

								    1.  Parish

								.Ed

								.Pp

								or even:

								.Bd -literal -offset indent

								    3. Bird

								    1. McHale

								    8. Parish

								.Ed

								.Pp

								you'd get the exact same HTML output. The point is, if you want to,

								you can use ordinal numbers in your ordered Markdown lists, so that

								the numbers in your source match the numbers in your published HTML.

								But if you want to be lazy, you don't have to.

								.Pp

								If you do use lazy list numbering, however, you should still start the

								list with the number 1. At some point in the future, Markdown may support

								starting ordered lists at an arbitrary number.

								.Pp

								List markers typically start at the left margin, but may be indented by

								up to three spaces. List markers must be followed by one or more spaces

								or a tab.

								.Pp

								To make lists look nice, you can wrap items with hanging indents:

								.Bd -literal -offset indent

								    *   Lorem ipsum dolor sit amet, consectetuer adipiscing

									elit. Aliquam hendrerit mi posuere lectus. Vestibulum

									enim wisi, viverra nec, fringilla in, laoreet vitae,

									risus.

								    *   Donec sit amet nisl. Aliquam semper ipsum sit amet

									velit. Suspendisse id sem consectetuer libero luctus

									adipiscing.

								.Ed

								.Pp

								But if you want to be lazy, you don't have to:

								.Bd -literal -offset indent

								    *   Lorem ipsum dolor sit amet, consectetuer adipiscing

								    elit. Aliquam hendrerit mi posuere lectus. Vestibulum

								    enim wisi, viverra nec, fringilla in, laoreet vitae,

								    risus.

								    *   Donec sit amet nisl. Aliquam semper ipsum sit amet

								    velit. Suspendisse id sem consectetuer libero luctus

								    adipiscing.

								.Ed

								.Pp

								If list items are separated by blank lines, Markdown will wrap the

								items in `<p>` tags in the HTML output. For example, this input:

								.Bd -literal -offset indent

								    *   Bird

								    *   Magic

								.Ed

								.Pp

								will turn into:

								.Bd -literal -offset indent

								    <ul>

								    <li>Bird</li>

								    <li>Magic</li>

								    </ul>

								.Ed

								.Pp

								But this:

								.Bd -literal -offset indent

								    *   Bird


								    *   Magic

								.Ed

								.Pp

								will turn into:

								.Bd -literal -offset indent

								    <ul>

								    <li><p>Bird</p></li>

								    <li><p>Magic</p></li>

								    </ul>

								.Ed

								.Pp

								List items may consist of multiple paragraphs. Each subsequent

								paragraph in a list item must be intended by either 4 spaces

								or one tab:

								.Bd -literal -offset indent

								    1.  This is a list item with two paragraphs. Lorem ipsum

									dolor sit amet, consectetuer adipiscing elit. Aliquam

									hendrerit mi posuere lectus.


								        Vestibulum enim wisi, viverra nec, fringilla in,

									laoreet vitae, risus. Donec sit amet nisl. Aliquam

									semper ipsum sit amet velit.


								    2.  Suspendisse id sem consectetuer libero luctus

									adipiscing.

								.Ed

								.Pp

								It looks nice if you indent every line of the subsequent

								paragraphs, but here again, Markdown will allow you to be

								lazy:

								.Bd -literal -offset indent

								    *   This is a list item with two paragraphs.


								        This is the second paragraph in the list item.

									You're only required to indent the first line. Lorem

									ipsum dolor sit amet, consectetuer adipiscing elit.


								    *   Another item in the same list.

								.Ed

								.Pp

								To put a blockquote within a list item, the blockquote's `>`

								delimiters need to be indented:

								.Bd -literal -offset indent

								    *   A list item with a blockquote:


								        > This is a blockquote

								        > inside a list item.

								.Ed

								.Pp

								To put a code block within a list item, the code block needs

								to be indented *twice* -- 8 spaces or two tabs:

								.Bd -literal -offset indent

								    *   A list item with a code block:


								            <code goes here>

								.Ed

								.Pp

								It's worth noting that it's possible to trigger an ordered list by

								accident, by writing something like this:

								.Bd -literal -offset indent

								    1986. What a great season.

								.Ed

								.Pp

								In other words, a *number-period-space* sequence at the beginning of a

								line. To avoid this, you can backslash-escape the period:

								.Bd -literal -offset indent

								    1986\\. What a great season.

								.Ed

								.Pp

								.Ss Code Blocks

								Pre-formatted code blocks are used for writing about programming or

								markup source code. Rather than forming normal paragraphs, the lines

								of a code block are interpreted literally. Markdown wraps a code block

								in both `<pre>` and `<code>` tags.

								.Pp

								To produce a code block in Markdown, simply indent every line of the

								block by at least 4 spaces or 1 tab. For example, given this input:

								.Bd -literal -offset indent

								    This is a normal paragraph:


								        This is a code block.

								.Ed

								.Pp

								.Nm

								will generate:

								.Bd -literal -offset indent

								    <p>This is a normal paragraph:</p>


								    <pre><code>This is a code block.

								    </code></pre>

								.Ed

								.Pp

								One level of indentation -- 4 spaces or 1 tab -- is removed from each

								line of the code block. For example, this:

								.Bd -literal -offset indent

								    Here is an example of AppleScript:


								        tell application "Foo"

								            beep

								        end tell

								.Ed

								.Pp

								will turn into:

								.Bd -literal -offset indent

								    <p>Here is an example of AppleScript:</p>


								    <pre><code>tell application "Foo"

								        beep

								    end tell

								    </code></pre>

								.Ed

								.Pp

								A code block continues until it reaches a line that is not indented

								(or the end of the article).

								.Pp

								Within a code block, ampersands (`&`) and angle brackets (`<` and `>`)

								are automatically converted into HTML entities. This makes it very

								easy to include example HTML source code using Markdown -- just paste

								it and indent it, and Markdown will handle the hassle of encoding the

								ampersands and angle brackets. For example, this:

								.Bd -literal -offset indent

								        <div class="footer">

								            &copy; 2004 Foo Corporation

								        </div>

								.Ed

								.Pp

								will turn into:

								.Bd -literal -offset indent

								    <pre><code>&lt;div class="footer"&gt;

								        &amp;copy; 2004 Foo Corporation

								    &lt;/div&gt;

								    </code></pre>

								.Ed

								.Pp

								Regular Markdown syntax is not processed within code blocks. E.g.,

								asterisks are just literal asterisks within a code block. This means

								it's also easy to use Markdown to write about Markdown's own syntax.

								.Ss Horizontal Rules

								You can produce a horizontal rule tag (`<hr />`) by placing three or

								more hyphens, asterisks, or underscores on a line by themselves. If you

								wish, you may use spaces between the hyphens or asterisks. Each of the

								following lines will produce a horizontal rule:

								.Bd -literal -offset indent

								    * * *


								    ***


								    *****


								    - - -


								    ---------------------------------------

								.Ed

								.Pp

								.Sh Span Elements

								.Ss Links

								.Nm

								supports two style of links:

								.Em inline

								and

								.Em reference .

								.Pp

								In both styles, the link text is delimited by [square brackets].

								.Pp

								To create an inline link, use a set of regular parentheses immediately

								after the link text's closing square bracket. Inside the parentheses,

								put the URL where you want the link to point, along with an *optional*

								title for the link, surrounded in quotes. For example:

								.Bd -literal -offset indent

								    This is [an example](http://example.com/ "Title") inline link.


								    [This link](http://example.net/) has no title attribute.

								.Ed

								.Pp

								Will produce:

								.Bd -literal -offset indent

								    <p>This is <a href="http://example.com/" title="Title">

								    an example</a> inline link.</p>


								    <p><a href="http://example.net/">This link</a> has no

								    title attribute.</p>

								.Ed

								.Pp

								If you're referring to a local resource on the same server, you can

								use relative paths:

								.Bd -literal -offset indent

								    See my [About](/about/) page for details.

								.Ed

								.Pp

								Reference-style links use a second set of square brackets, inside

								which you place a label of your choosing to identify the link:

								.Bd -literal -offset indent

								    This is [an example][id] reference-style link.

								.Ed

								.Pp

								You can optionally use a space to separate the sets of brackets:

								.Bd -literal -offset indent

								    This is [an example] [id] reference-style link.

								.Ed

								.Pp

								Then, anywhere in the document, you define your link label like this,

								on a line by itself:

								.Bd -literal -offset indent

								    [id]: http://example.com/  "Optional Title Here"

								.Ed

								.Pp

								That is:

								.Bl -bullet

								.It

								Square brackets containing the link identifier (optionally

								indented from the left margin using up to three spaces);

								.It

								followed by a colon;

								.It

								followed by one or more spaces (or tabs);

								.It

								followed by the URL for the link;

								.It

								optionally followed by a title attribute for the link, enclosed

								in double or single quotes, or enclosed in parentheses.

								.El

								.Pp

								The following three link definitions are equivalent:

								.Bd -literal -offset indent

									[foo]: http://example.com/  "Optional Title Here"

									[foo]: http://example.com/  'Optional Title Here'

									[foo]: http://example.com/  (Optional Title Here)

								.Ed

								.Pp

								.Em Note :

								There is a known bug in Markdown.pl 1.0.1 which prevents

								single quotes from being used to delimit link titles.

								.Pp

								The link URL may, optionally, be surrounded by angle brackets:

								.Bd -literal -offset indent

								    [id]: <http://example.com/>  "Optional Title Here"

								.Ed

								.Pp

								You can put the title attribute on the next line and use extra spaces

								or tabs for padding, which tends to look better with longer URLs:

								.Bd -literal -offset indent

								    [id]: http://example.com/longish/path/to/resource/here

								        "Optional Title Here"

								.Ed

								.Pp

								Link definitions are only used for creating links during Markdown

								processing, and are stripped from your document in the HTML output.

								.Pp

								Link definition names may constist of letters, numbers, spaces, and

								punctuation -- but they are

								.Em not

								case sensitive. E.g. these two

								links:

								.Bd -literal -offset indent

									[link text][a]

									[link text][A]

								.Ed

								.Pp

								are equivalent.

								.Pp

								The

								.Em implicit link name

								shortcut allows you to omit the name of the

								link, in which case the link text itself is used as the name.

								Just use an empty set of square brackets -- e.g., to link the word

								.Qq Google

								to the google.com web site, you could simply write:

								.Bd -literal -offset indent

									[Google][]

								.Ed

								.Pp

								And then define the link:

								.Bd -literal -offset indent

									[Google]: http://google.com/

								.Ed

								.Pp

								Because link names may contain spaces, this shortcut even works for

								multiple words in the link text:

								.Bd -literal -offset indent

									Visit [Daring Fireball][] for more information.

								.Ed

								.Pp

								And then define the link:

								.Bd -literal -offset indent

									[Daring Fireball]: http://daringfireball.net/

								.Ed

								.Pp

								Link definitions can be placed anywhere in your Markdown document. I

								tend to put them immediately after each paragraph in which they're

								used, but if you want, you can put them all at the end of your

								document, sort of like footnotes.

								.Pp

								Here's an example of reference links in action:

								.Bd -literal -offset indent

								    I get 10 times more traffic from [Google] [1] than from

								    [Yahoo] [2] or [MSN] [3].


								      [1]: http://google.com/        "Google"

								      [2]: http://search.yahoo.com/  "Yahoo Search"

								      [3]: http://search.msn.com/    "MSN Search"

								.Ed

								.Pp

								Using the implicit link name shortcut, you could instead write:

								.Bd -literal -offset indent

								    I get 10 times more traffic from [Google][] than from

								    [Yahoo][] or [MSN][].


								      [google]: http://google.com/        "Google"

								      [yahoo]:  http://search.yahoo.com/  "Yahoo Search"

								      [msn]:    http://search.msn.com/    "MSN Search"

								.Ed

								.Pp

								Both of the above examples will produce the following HTML output:

								.Bd -literal -offset indent

								    <p>I get 10 times more traffic from <a href="http://google.com/"

								    title="Google">Google</a> than from

								    <a href="http://search.yahoo.com/" title="Yahoo Search">Yahoo</a>

								    or

								    <a href="http://search.msn.com/" title="MSN Search">MSN</a>.</p>

								.Ed

								.Pp

								For comparison, here is the same paragraph written using

								Markdown's inline link style:

								.Bd -literal -offset indent

								    I get 10 times more traffic from

								    [Google](http://google.com/ "Google") than from

								    [Yahoo](http://search.yahoo.com/ "Yahoo Search") or

								    [MSN](http://search.msn.com/ "MSN Search").

								.Ed

								.Pp

								The point of reference-style links is not that they're easier to

								write. The point is that with reference-style links, your document

								source is vastly more readable. Compare the above examples: using

								reference-style links, the paragraph itself is only 81 characters

								long; with inline-style links, it's 176 characters; and as raw HTML,

								it's 234 characters. In the raw HTML, there's more markup than there

								is text.

								.Pp

								With Markdown's reference-style links, a source document much more

								closely resembles the final output, as rendered in a browser. By

								allowing you to move the markup-related metadata out of the paragraph,

								you can add links without interrupting the narrative flow of your

								prose.

								.Ss Emphasis

								Markdown treats asterisks (`*`) and underscores (`_`) as indicators of

								emphasis. Text wrapped with one `*` or `_` will be wrapped with an

								HTML `<em>` tag; double `*`'s or `_`'s will be wrapped with an HTML

								`<strong>` tag. E.g., this input:

								.Bd -literal -offset indent

								    *single asterisks*


								    _single underscores_


								    **double asterisks**


								    __double underscores__

								.Ed

								.Pp

								will produce:

								.Bd -literal -offset indent

								    <em>single asterisks</em>


								    <em>single underscores</em>


								    <strong>double asterisks</strong>


								    <strong>double underscores</strong>

								.Ed

								.Pp

								You can use whichever style you prefer; the lone restriction is that

								the same character must be used to open and close an emphasis span.

								.Pp

								Emphasis can be used in the middle of a word:

								.Bd -literal -offset indent

								    un*fucking*believable

								.Ed

								.Pp

								But if you surround an `*` or `_` with spaces, it'll be treated as a

								literal asterisk or underscore.

								.Pp

								To produce a literal asterisk or underscore at a position where it

								would otherwise be used as an emphasis delimiter, you can backslash

								escape it:

								.Bd -literal -offset indent

								    \\*this text is surrounded by literal asterisks\\*

								.Ed

								.Pp

								.Ss Code

								To indicate a span of code, wrap it with backtick quotes (`` ` ``).

								Unlike a pre-formatted code block, a code span indicates code within a

								normal paragraph. For example:

								.Bd -literal -offset indent

								    Use the `printf()` function.

								.Ed

								.Pp

								will produce:

								.Bd -literal -offset indent

								    <p>Use the <code>printf()</code> function.</p>

								.Ed

								.Pp

								To include a literal backtick character within a code span, you can use

								multiple backticks as the opening and closing delimiters:

								.Bd -literal -offset indent

								    ``There is a literal backtick (`) here.``

								.Ed

								.Pp

								which will produce this:

								.Bd -literal -offset indent

								    <p><code>There is a literal backtick (`) here.</code></p>

								.Ed

								.Pp

								The backtick delimiters surrounding a code span may include spaces --

								one after the opening, one before the closing. This allows you to place

								literal backtick characters at the beginning or end of a code span:

								.Bd -literal -offset indent

									A single backtick in a code span: `` ` ``


									A backtick-delimited string in a code span: `` `foo` ``

								.Ed

								.Pp

								will produce:

								.Bd -literal -offset indent

									<p>A single backtick in a code span: <code>`</code></p>


									<p>A backtick-delimited string in a code span: <code>`foo`</code></p>

								.Ed

								.Pp

								With a code span, ampersands and angle brackets are encoded as HTML

								entities automatically, which makes it easy to include example HTML

								tags. Markdown will turn this:

								.Bd -literal -offset indent

								    Please don't use any `<blink>` tags.

								.Ed

								.Pp

								into:

								.Bd -literal -offset indent

								    <p>Please don't use any <code>&lt;blink&gt;</code> tags.</p>

								.Ed

								.Pp

								You can write this:

								.Bd -literal -offset indent

								    `&#8212;` is the decimal-encoded equivalent of `&mdash;`.

								.Ed

								.Pp

								to produce:

								.Bd -literal -offset indent

								    <p><code>&amp;#8212;</code> is the decimal-encoded

								    equivalent of <code>&amp;mdash;</code>.</p>

								.Ed

								.Pp

								.Ss Images

								Admittedly, it's fairly difficult to devise a

								.Qq natural

								syntax for placing images into a plain text document format.

								.Pp

								Markdown uses an image syntax that is intended to resemble the syntax

								for links, allowing for two styles:

								.Em inline

								and

								.Em reference .

								.Pp

								Inline image syntax looks like this:

								.Bd -literal -offset indent

								    ![Alt text](/path/to/img.jpg)


								    ![Alt text](/path/to/img.jpg =Optional size "Optional title")

								.Ed

								.Pp

								That is:

								.Bl -bullet

								.It

								An exclamation mark: `!`;

								.It

								followed by a set of square brackets, containing the `alt`

								attribute text for the image;

								.It

								followed by a set of parentheses, containing the URL or path to

								the image, an optional `size` attribute (in

								.Ar width Li c Ar height

								format) prefixed with a `=`,

								and an optional `title` attribute enclosed in double

								or single quotes.

								.El

								.Pp

								Reference-style image syntax looks like this:

								.Bd -literal -offset indent

								    ![Alt text][id]

								.Ed

								.Pp

								Where

								.Qq id

								is the name of a defined image reference. Image references

								are defined using syntax identical to link references:

								.Bd -literal -offset indent

								    [id]: url/to/image  =Optional size "Optional title attribute"

								.Ed

								.Pp

								.Sh Miscellaneous

								.Ss Automatic Links

								.Nm

								supports a shortcut style for creating

								.Qq automatic

								links for URLs and email addresses: simply surround the URL or email

								address with angle brackets. What this means is that if you want to

								 show the actual text of a URL or email address, and also have it be

								  a clickable link, you can do this:

								.Bd -literal -offset indent

								    <http://example.com/>

								.Ed

								.Pp

								.Nm

								will turn this into:

								.Bd -literal -offset indent

								    <a href="http://example.com/">http://example.com/</a>

								.Ed

								.Pp

								Automatic links for email addresses work similarly, except that

								Markdown will also perform a bit of randomized decimal and hex

								entity-encoding to help obscure your address from address-harvesting

								spambots. For example, Markdown will turn this:

								.Bd -literal -offset indent

								    <address@example.com>

								.Ed

								.Pp

								into something like this:

								.Bd -literal -offset indent

								    <a href="&#x6D;&#x61;i&#x6C;&#x74;&#x6F;:&#x61;&#x64;&#x64;&#x72;&#x65;

								    &#115;&#115;&#64;&#101;&#120;&#x61;&#109;&#x70;&#x6C;e&#x2E;&#99;&#111;

								    &#109;">&#x61;&#x64;&#x64;&#x72;&#x65;&#115;&#115;&#64;&#101;&#120;&#x61;

								    &#109;&#x70;&#x6C;e&#x2E;&#99;&#111;&#109;</a>

								.Ed

								.Pp

								which will render in a browser as a clickable link to

								.Qq address@example.com .

								.Pp

								(This sort of entity-encoding trick will indeed fool many, if not

								most, address-harvesting bots, but it definitely won't fool all of

								them. It's better than nothing, but an address published in this way

								will probably eventually start receiving spam.)

								.Ss Backslash Escapes

								.Nm

								allows you to use backslash escapes to generate literal

								characters which would otherwise have special meaning in Markdown's

								formatting syntax. For example, if you wanted to surround a word with

								literal asterisks (instead of an HTML `<em>` tag), you add backslashes

								before the asterisks, like this:

								.Bd -literal -offset indent

								    \\*literal asterisks\\*

								.Ed

								.Pp

								.Nm

								provides backslash escapes for the following characters:

								.Bl -tag -compact

								.It \&\

								backslash

								.It \`

								backtick

								.It *

								asterisk

								.It _

								underscore

								.It \{\}

								curly braces

								.It []

								square brackets

								.It ()

								parentheses

								.It #

								hash mark

								.It +

								plus sign

								.It \-

								minus sign (hyphen)

								.It \.

								dot

								.It \!

								exclamation mark

								.El

								.Sh BUGS

								.Nm

								assumes that tabs are set to 4 spaces.

								.Sh AUTHOR

								John Gruber

								.%T http://daringfireball.net/

								.Sh SEE ALSO

								.Xr markdown 1 ,

								.Xr markdown 3 ,

								.Xr mkd-callbacks 3 ,

								.Xr mkd-functions 3 ,

								.Xr mkd-extensions 7 .

								.Pp

								.%T http://daringfireball.net/projects/markdown

								.br

								.%T http://docutils.sourceforge.net/mirror/setext.html

								.br

								.%T http://www.aaronsw.com/2002/atx/

								.br

								.%T http://textism.com/tools/textile/

								.br

								.%T http://docutils.sourceforge.net/rst.html

								.br

								.%T http://www.triptico.com/software/grutatxt.html

								.br

								.%T http://ettext.taint.org/doc/