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+Markdown: Syntax
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+================
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+
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+<ul id="ProjectSubmenu">
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+ <li><a href="/projects/markdown/" title="Markdown Project Page">Main</a></li>
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+ <li><a href="/projects/markdown/basics" title="Markdown Basics">Basics</a></li>
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+ <li><a class="selected" title="Markdown Syntax Documentation">Syntax</a></li>
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+ <li><a href="/projects/markdown/license" title="Pricing and License Information">License</a></li>
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+ <li><a href="/projects/markdown/dingus" title="Online Markdown Web Form">Dingus</a></li>
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+</ul>
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+
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+
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+* [Overview](#overview)
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+ * [Philosophy](#philosophy)
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+ * [Inline HTML](#html)
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+ * [Automatic Escaping for Special Characters](#autoescape)
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+* [Block Elements](#block)
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+ * [Paragraphs and Line Breaks](#p)
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+ * [Headers](#header)
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+ * [Blockquotes](#blockquote)
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+ * [Lists](#list)
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+ * [Code Blocks](#precode)
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+ * [Horizontal Rules](#hr)
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+* [Span Elements](#span)
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+ * [Links](#link)
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+ * [Emphasis](#em)
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+ * [Code](#code)
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+ * [Images](#img)
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+* [Miscellaneous](#misc)
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+ * [Backslash Escapes](#backslash)
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+ * [Automatic Links](#autolink)
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+
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+
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+**Note:** This document is itself written using Markdown; you
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+can [see the source for it by adding '.text' to the URL][src].
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+
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+ [src]: /projects/markdown/syntax.text
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+
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+* * *
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+
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+<h2 id="overview">Overview</h2>
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+
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+<h3 id="philosophy">Philosophy</h3>
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+
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+Markdown is intended to be as easy-to-read and easy-to-write as is feasible.
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+
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+Readability, however, is emphasized above all else. A Markdown-formatted
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+document should be publishable as-is, as plain text, without looking
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+like it's been marked up with tags or formatting instructions. While
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+Markdown's syntax has been influenced by several existing text-to-HTML
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+filters -- including [Setext] [1], [atx] [2], [Textile] [3], [reStructuredText] [4],
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+[Grutatext] [5], and [EtText] [6] -- the single biggest source of
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+inspiration for Markdown's syntax is the format of plain text email.
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+
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+ [1]: http://docutils.sourceforge.net/mirror/setext.html
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+ [2]: http://www.aaronsw.com/2002/atx/
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+ [3]: http://textism.com/tools/textile/
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+ [4]: http://docutils.sourceforge.net/rst.html
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+ [5]: http://www.triptico.com/software/grutatxt.html
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+ [6]: http://ettext.taint.org/doc/
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+
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+To this end, Markdown's syntax is comprised entirely of punctuation
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+characters, which punctuation characters have been carefully chosen so
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+as to look like what they mean. E.g., asterisks around a word actually
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+look like \*emphasis\*. Markdown lists look like, well, lists. Even
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+blockquotes look like quoted passages of text, assuming you've ever
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+used email.
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+
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+
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+
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+<h3 id="html">Inline HTML</h3>
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+
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+Markdown's syntax is intended for one purpose: to be used as a
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+format for *writing* for the web.
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+
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+Markdown is not a replacement for HTML, or even close to it. Its
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+syntax is very small, corresponding only to a very small subset of
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+HTML tags. The idea is *not* to create a syntax that makes it easier
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+to insert HTML tags. In my opinion, HTML tags are already easy to
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+insert. The idea for Markdown is to make it easy to read, write, and
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+edit prose. HTML is a *publishing* format; Markdown is a *writing*
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+format. Thus, Markdown's formatting syntax only addresses issues that
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+can be conveyed in plain text.
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+
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+For any markup that is not covered by Markdown's syntax, you simply
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+use HTML itself. There's no need to preface it or delimit it to
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+indicate that you're switching from Markdown to HTML; you just use
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+the tags.
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+
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+The only restrictions are that block-level HTML elements -- e.g. `<div>`,
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+`<table>`, `<pre>`, `<p>`, etc. -- must be separated from surrounding
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+content by blank lines, and the start and end tags of the block should
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+not be indented with tabs or spaces. Markdown is smart enough not
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+to add extra (unwanted) `<p>` tags around HTML block-level tags.
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+
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+For example, to add an HTML table to a Markdown article:
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+
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+ This is a regular paragraph.
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+
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+ <table>
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+ <tr>
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+ <td>Foo</td>
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+ </tr>
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+ </table>
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+
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+ This is another regular paragraph.
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+
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+Note that Markdown formatting syntax is not processed within block-level
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+HTML tags. E.g., you can't use Markdown-style `*emphasis*` inside an
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+HTML block.
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+
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+Span-level HTML tags -- e.g. `<span>`, `<cite>`, or `<del>` -- can be
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+used anywhere in a Markdown paragraph, list item, or header. If you
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+want, you can even use HTML tags instead of Markdown formatting; e.g. if
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+you'd prefer to use HTML `<a>` or `<img>` tags instead of Markdown's
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+link or image syntax, go right ahead.
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+
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+Unlike block-level HTML tags, Markdown syntax *is* processed within
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+span-level tags.
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+
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+
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+<h3 id="autoescape">Automatic Escaping for Special Characters</h3>
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+
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+In HTML, there are two characters that demand special treatment: `<`
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+and `&`. Left angle brackets are used to start tags; ampersands are
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+used to denote HTML entities. If you want to use them as literal
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+characters, you must escape them as entities, e.g. `<`, and
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+`&`.
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+
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+Ampersands in particular are bedeviling for web writers. If you want to
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+write about 'AT&T', you need to write '`AT&T`'. You even need to
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+escape ampersands within URLs. Thus, if you want to link to:
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+
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+ http://images.google.com/images?num=30&q=larry+bird
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+
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+you need to encode the URL as:
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+
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+ http://images.google.com/images?num=30&q=larry+bird
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+
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+in your anchor tag `href` attribute. Needless to say, this is easy to
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+forget, and is probably the single most common source of HTML validation
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+errors in otherwise well-marked-up web sites.
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+
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+Markdown allows you to use these characters naturally, taking care of
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+all the necessary escaping for you. If you use an ampersand as part of
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+an HTML entity, it remains unchanged; otherwise it will be translated
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+into `&`.
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+
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+So, if you want to include a copyright symbol in your article, you can write:
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+
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+ ©
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+
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+and Markdown will leave it alone. But if you write:
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+
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+ AT&T
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+
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+Markdown will translate it to:
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+
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+ AT&T
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+
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+Similarly, because Markdown supports [inline HTML](#html), if you use
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+angle brackets as delimiters for HTML tags, Markdown will treat them as
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+such. But if you write:
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+
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+ 4 < 5
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+
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+Markdown will translate it to:
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+
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+ 4 < 5
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+
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+However, inside Markdown code spans and blocks, angle brackets and
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+ampersands are *always* encoded automatically. This makes it easy to use
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+Markdown to write about HTML code. (As opposed to raw HTML, which is a
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+terrible format for writing about HTML syntax, because every single `<`
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+and `&` in your example code needs to be escaped.)
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+
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+
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+* * *
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+
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+
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+<h2 id="block">Block Elements</h2>
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+
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+
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+<h3 id="p">Paragraphs and Line Breaks</h3>
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+
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+A paragraph is simply one or more consecutive lines of text, separated
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+by one or more blank lines. (A blank line is any line that looks like a
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+blank line -- a line containing nothing but spaces or tabs is considered
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+blank.) Normal paragraphs should not be indented with spaces or tabs.
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+
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+The implication of the "one or more consecutive lines of text" rule is
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+that Markdown supports "hard-wrapped" text paragraphs. This differs
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+significantly from most other text-to-HTML formatters (including Movable
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+Type's "Convert Line Breaks" option) which translate every line break
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+character in a paragraph into a `<br />` tag.
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+
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+When you *do* want to insert a `<br />` break tag using Markdown, you
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+end a line with two or more spaces, then type return.
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+
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+Yes, this takes a tad more effort to create a `<br />`, but a simplistic
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+"every line break is a `<br />`" rule wouldn't work for Markdown.
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+Markdown's email-style [blockquoting][bq] and multi-paragraph [list items][l]
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+work best -- and look better -- when you format them with hard breaks.
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+
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+ [bq]: #blockquote
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+ [l]: #list
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+
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+
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+
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+<h3 id="header">Headers</h3>
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+
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+Markdown supports two styles of headers, [Setext] [1] and [atx] [2].
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+
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+Setext-style headers are "underlined" using equal signs (for first-level
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+headers) and dashes (for second-level headers). For example:
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+
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+ This is an H1
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+ =============
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+
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+ This is an H2
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+ -------------
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+
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+Any number of underlining `=`'s or `-`'s will work.
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+
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+Atx-style headers use 1-6 hash characters at the start of the line,
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+corresponding to header levels 1-6. For example:
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+
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+ # This is an H1
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+
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+ ## This is an H2
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+
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+ ###### This is an H6
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+
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+Optionally, you may "close" atx-style headers. This is purely
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+cosmetic -- you can use this if you think it looks better. The
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+closing hashes don't even need to match the number of hashes
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+used to open the header. (The number of opening hashes
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+determines the header level.) :
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+
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+ # This is an H1 #
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+
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+ ## This is an H2 ##
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+
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+ ### This is an H3 ######
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+
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+
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+<h3 id="blockquote">Blockquotes</h3>
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+
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+Markdown uses email-style `>` characters for blockquoting. If you're
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+familiar with quoting passages of text in an email message, then you
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+know how to create a blockquote in Markdown. It looks best if you hard
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+wrap the text and put a `>` before every line:
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+
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+ > This is a blockquote with two paragraphs. Lorem ipsum dolor sit amet,
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+ > consectetuer adipiscing elit. Aliquam hendrerit mi posuere lectus.
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+ > Vestibulum enim wisi, viverra nec, fringilla in, laoreet vitae, risus.
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+ >
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+ > Donec sit amet nisl. Aliquam semper ipsum sit amet velit. Suspendisse
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+ > id sem consectetuer libero luctus adipiscing.
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+
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+Markdown allows you to be lazy and only put the `>` before the first
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+line of a hard-wrapped paragraph:
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+
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+ > This is a blockquote with two paragraphs. Lorem ipsum dolor sit amet,
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+ consectetuer adipiscing elit. Aliquam hendrerit mi posuere lectus.
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+ Vestibulum enim wisi, viverra nec, fringilla in, laoreet vitae, risus.
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+
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+ > Donec sit amet nisl. Aliquam semper ipsum sit amet velit. Suspendisse
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+ id sem consectetuer libero luctus adipiscing.
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+
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+Blockquotes can be nested (i.e. a blockquote-in-a-blockquote) by
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+adding additional levels of `>`:
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+
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+ > This is the first level of quoting.
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+ >
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+ > > This is nested blockquote.
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+ >
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+ > Back to the first level.
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+
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+Blockquotes can contain other Markdown elements, including headers, lists,
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+and code blocks:
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+
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+ > ## This is a header.
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+ >
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+ > 1. This is the first list item.
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+ > 2. This is the second list item.
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+ >
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+ > Here's some example code:
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+ >
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+ > return shell_exec("echo $input | $markdown_script");
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+
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+Any decent text editor should make email-style quoting easy. For
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+example, with BBEdit, you can make a selection and choose Increase
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+Quote Level from the Text menu.
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+
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+
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+<h3 id="list">Lists</h3>
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+
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+Markdown supports ordered (numbered) and unordered (bulleted) lists.
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+
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+Unordered lists use asterisks, pluses, and hyphens -- interchangably
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+-- as list markers:
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+
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+ * Red
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+ * Green
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+ * Blue
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+
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+is equivalent to:
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+
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+ + Red
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+ + Green
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+ + Blue
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+
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+and:
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+
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+ - Red
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+ - Green
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+ - Blue
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+
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+Ordered lists use numbers followed by periods:
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+
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+ 1. Bird
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+ 2. McHale
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+ 3. Parish
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+
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+It's important to note that the actual numbers you use to mark the
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+list have no effect on the HTML output Markdown produces. The HTML
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+Markdown produces from the above list is:
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+
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+ <ol>
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+ <li>Bird</li>
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+ <li>McHale</li>
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+ <li>Parish</li>
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+ </ol>
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+
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+If you instead wrote the list in Markdown like this:
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+
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+ 1. Bird
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+ 1. McHale
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+ 1. Parish
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+
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+or even:
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+
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+ 3. Bird
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+ 1. McHale
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+ 8. Parish
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+
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+you'd get the exact same HTML output. The point is, if you want to,
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+you can use ordinal numbers in your ordered Markdown lists, so that
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+the numbers in your source match the numbers in your published HTML.
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+But if you want to be lazy, you don't have to.
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+
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+If you do use lazy list numbering, however, you should still start the
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+list with the number 1. At some point in the future, Markdown may support
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+starting ordered lists at an arbitrary number.
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+
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+List markers typically start at the left margin, but may be indented by
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+up to three spaces. List markers must be followed by one or more spaces
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+or a tab.
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+
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+To make lists look nice, you can wrap items with hanging indents:
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+
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+ * Lorem ipsum dolor sit amet, consectetuer adipiscing elit.
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+ Aliquam hendrerit mi posuere lectus. Vestibulum enim wisi,
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+ viverra nec, fringilla in, laoreet vitae, risus.
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+ * Donec sit amet nisl. Aliquam semper ipsum sit amet velit.
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+ Suspendisse id sem consectetuer libero luctus adipiscing.
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+
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+But if you want to be lazy, you don't have to:
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+
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+ * Lorem ipsum dolor sit amet, consectetuer adipiscing elit.
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+ Aliquam hendrerit mi posuere lectus. Vestibulum enim wisi,
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+ viverra nec, fringilla in, laoreet vitae, risus.
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+ * Donec sit amet nisl. Aliquam semper ipsum sit amet velit.
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+ Suspendisse id sem consectetuer libero luctus adipiscing.
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+
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+If list items are separated by blank lines, Markdown will wrap the
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+items in `<p>` tags in the HTML output. For example, this input:
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+
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+ * Bird
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+ * Magic
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+
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+will turn into:
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+
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+ <ul>
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+ <li>Bird</li>
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+ <li>Magic</li>
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+ </ul>
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+
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+But this:
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+
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+ * Bird
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+
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+ * Magic
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+
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+will turn into:
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+
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+ <ul>
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+ <li><p>Bird</p></li>
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+ <li><p>Magic</p></li>
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+ </ul>
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+
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+List items may consist of multiple paragraphs. Each subsequent
|
|
|
+paragraph in a list item must be indented by either 4 spaces
|
|
|
+or one tab:
|
|
|
+
|
|
|
+ 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.
|
|
|
+
|
|
|
+It looks nice if you indent every line of the subsequent
|
|
|
+paragraphs, but here again, Markdown will allow you to be
|
|
|
+lazy:
|
|
|
+
|
|
|
+ * 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.
|
|
|
+
|
|
|
+To put a blockquote within a list item, the blockquote's `>`
|
|
|
+delimiters need to be indented:
|
|
|
+
|
|
|
+ * A list item with a blockquote:
|
|
|
+
|
|
|
+ > This is a blockquote
|
|
|
+ > inside a list item.
|
|
|
+
|
|
|
+To put a code block within a list item, the code block needs
|
|
|
+to be indented *twice* -- 8 spaces or two tabs:
|
|
|
+
|
|
|
+ * A list item with a code block:
|
|
|
+
|
|
|
+ <code goes here>
|
|
|
+
|
|
|
+
|
|
|
+It's worth noting that it's possible to trigger an ordered list by
|
|
|
+accident, by writing something like this:
|
|
|
+
|
|
|
+ 1986. What a great season.
|
|
|
+
|
|
|
+In other words, a *number-period-space* sequence at the beginning of a
|
|
|
+line. To avoid this, you can backslash-escape the period:
|
|
|
+
|
|
|
+ 1986\. What a great season.
|
|
|
+
|
|
|
+
|
|
|
+
|
|
|
+<h3 id="precode">Code Blocks</h3>
|
|
|
+
|
|
|
+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.
|
|
|
+
|
|
|
+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:
|
|
|
+
|
|
|
+ This is a normal paragraph:
|
|
|
+
|
|
|
+ This is a code block.
|
|
|
+
|
|
|
+Markdown will generate:
|
|
|
+
|
|
|
+ <p>This is a normal paragraph:</p>
|
|
|
+
|
|
|
+ <pre><code>This is a code block.
|
|
|
+ </code></pre>
|
|
|
+
|
|
|
+One level of indentation -- 4 spaces or 1 tab -- is removed from each
|
|
|
+line of the code block. For example, this:
|
|
|
+
|
|
|
+ Here is an example of AppleScript:
|
|
|
+
|
|
|
+ tell application "Foo"
|
|
|
+ beep
|
|
|
+ end tell
|
|
|
+
|
|
|
+will turn into:
|
|
|
+
|
|
|
+ <p>Here is an example of AppleScript:</p>
|
|
|
+
|
|
|
+ <pre><code>tell application "Foo"
|
|
|
+ beep
|
|
|
+ end tell
|
|
|
+ </code></pre>
|
|
|
+
|
|
|
+A code block continues until it reaches a line that is not indented
|
|
|
+(or the end of the article).
|
|
|
+
|
|
|
+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:
|
|
|
+
|
|
|
+ <div class="footer">
|
|
|
+ © 2004 Foo Corporation
|
|
|
+ </div>
|
|
|
+
|
|
|
+will turn into:
|
|
|
+
|
|
|
+ <pre><code><div class="footer">
|
|
|
+ &copy; 2004 Foo Corporation
|
|
|
+ </div>
|
|
|
+ </code></pre>
|
|
|
+
|
|
|
+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.
|
|
|
+
|
|
|
+
|
|
|
+
|
|
|
+<h3 id="hr">Horizontal Rules</h3>
|
|
|
+
|
|
|
+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:
|
|
|
+
|
|
|
+ * * *
|
|
|
+
|
|
|
+ ***
|
|
|
+
|
|
|
+ *****
|
|
|
+
|
|
|
+ - - -
|
|
|
+
|
|
|
+ ---------------------------------------
|
|
|
+
|
|
|
+
|
|
|
+* * *
|
|
|
+
|
|
|
+<h2 id="span">Span Elements</h2>
|
|
|
+
|
|
|
+<h3 id="link">Links</h3>
|
|
|
+
|
|
|
+Markdown supports two style of links: *inline* and *reference*.
|
|
|
+
|
|
|
+In both styles, the link text is delimited by [square brackets].
|
|
|
+
|
|
|
+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:
|
|
|
+
|
|
|
+ This is [an example](http://example.com/ "Title") inline link.
|
|
|
+
|
|
|
+ [This link](http://example.net/) has no title attribute.
|
|
|
+
|
|
|
+Will produce:
|
|
|
+
|
|
|
+ <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>
|
|
|
+
|
|
|
+If you're referring to a local resource on the same server, you can
|
|
|
+use relative paths:
|
|
|
+
|
|
|
+ See my [About](/about/) page for details.
|
|
|
+
|
|
|
+Reference-style links use a second set of square brackets, inside
|
|
|
+which you place a label of your choosing to identify the link:
|
|
|
+
|
|
|
+ This is [an example][id] reference-style link.
|
|
|
+
|
|
|
+You can optionally use a space to separate the sets of brackets:
|
|
|
+
|
|
|
+ This is [an example] [id] reference-style link.
|
|
|
+
|
|
|
+Then, anywhere in the document, you define your link label like this,
|
|
|
+on a line by itself:
|
|
|
+
|
|
|
+ [id]: http://example.com/ "Optional Title Here"
|
|
|
+
|
|
|
+That is:
|
|
|
+
|
|
|
+* Square brackets containing the link identifier (optionally
|
|
|
+ indented from the left margin using up to three spaces);
|
|
|
+* followed by a colon;
|
|
|
+* followed by one or more spaces (or tabs);
|
|
|
+* followed by the URL for the link;
|
|
|
+* optionally followed by a title attribute for the link, enclosed
|
|
|
+ in double or single quotes, or enclosed in parentheses.
|
|
|
+
|
|
|
+The following three link definitions are equivalent:
|
|
|
+
|
|
|
+ [foo]: http://example.com/ "Optional Title Here"
|
|
|
+ [foo]: http://example.com/ 'Optional Title Here'
|
|
|
+ [foo]: http://example.com/ (Optional Title Here)
|
|
|
+
|
|
|
+**Note:** There is a known bug in Markdown.pl 1.0.1 which prevents
|
|
|
+single quotes from being used to delimit link titles.
|
|
|
+
|
|
|
+The link URL may, optionally, be surrounded by angle brackets:
|
|
|
+
|
|
|
+ [id]: <http://example.com/> "Optional Title Here"
|
|
|
+
|
|
|
+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:
|
|
|
+
|
|
|
+ [id]: http://example.com/longish/path/to/resource/here
|
|
|
+ "Optional Title Here"
|
|
|
+
|
|
|
+Link definitions are only used for creating links during Markdown
|
|
|
+processing, and are stripped from your document in the HTML output.
|
|
|
+
|
|
|
+Link definition names may consist of letters, numbers, spaces, and
|
|
|
+punctuation -- but they are *not* case sensitive. E.g. these two
|
|
|
+links:
|
|
|
+
|
|
|
+ [link text][a]
|
|
|
+ [link text][A]
|
|
|
+
|
|
|
+are equivalent.
|
|
|
+
|
|
|
+The *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
|
|
|
+"Google" to the google.com web site, you could simply write:
|
|
|
+
|
|
|
+ [Google][]
|
|
|
+
|
|
|
+And then define the link:
|
|
|
+
|
|
|
+ [Google]: http://google.com/
|
|
|
+
|
|
|
+Because link names may contain spaces, this shortcut even works for
|
|
|
+multiple words in the link text:
|
|
|
+
|
|
|
+ Visit [Daring Fireball][] for more information.
|
|
|
+
|
|
|
+And then define the link:
|
|
|
+
|
|
|
+ [Daring Fireball]: http://daringfireball.net/
|
|
|
+
|
|
|
+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.
|
|
|
+
|
|
|
+Here's an example of reference links in action:
|
|
|
+
|
|
|
+ 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"
|
|
|
+
|
|
|
+Using the implicit link name shortcut, you could instead write:
|
|
|
+
|
|
|
+ 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"
|
|
|
+
|
|
|
+Both of the above examples will produce the following HTML output:
|
|
|
+
|
|
|
+ <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>
|
|
|
+
|
|
|
+For comparison, here is the same paragraph written using
|
|
|
+Markdown's inline link style:
|
|
|
+
|
|
|
+ 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").
|
|
|
+
|
|
|
+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.
|
|
|
+
|
|
|
+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.
|
|
|
+
|
|
|
+
|
|
|
+<h3 id="em">Emphasis</h3>
|
|
|
+
|
|
|
+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:
|
|
|
+
|
|
|
+ *single asterisks*
|
|
|
+
|
|
|
+ _single underscores_
|
|
|
+
|
|
|
+ **double asterisks**
|
|
|
+
|
|
|
+ __double underscores__
|
|
|
+
|
|
|
+will produce:
|
|
|
+
|
|
|
+ <em>single asterisks</em>
|
|
|
+
|
|
|
+ <em>single underscores</em>
|
|
|
+
|
|
|
+ <strong>double asterisks</strong>
|
|
|
+
|
|
|
+ <strong>double underscores</strong>
|
|
|
+
|
|
|
+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.
|
|
|
+
|
|
|
+Emphasis can be used in the middle of a word:
|
|
|
+
|
|
|
+ un*frigging*believable
|
|
|
+
|
|
|
+But if you surround an `*` or `_` with spaces, it'll be treated as a
|
|
|
+literal asterisk or underscore.
|
|
|
+
|
|
|
+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:
|
|
|
+
|
|
|
+ \*this text is surrounded by literal asterisks\*
|
|
|
+
|
|
|
+
|
|
|
+
|
|
|
+<h3 id="code">Code</h3>
|
|
|
+
|
|
|
+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:
|
|
|
+
|
|
|
+ Use the `printf()` function.
|
|
|
+
|
|
|
+will produce:
|
|
|
+
|
|
|
+ <p>Use the <code>printf()</code> function.</p>
|
|
|
+
|
|
|
+To include a literal backtick character within a code span, you can use
|
|
|
+multiple backticks as the opening and closing delimiters:
|
|
|
+
|
|
|
+ ``There is a literal backtick (`) here.``
|
|
|
+
|
|
|
+which will produce this:
|
|
|
+
|
|
|
+ <p><code>There is a literal backtick (`) here.</code></p>
|
|
|
+
|
|
|
+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:
|
|
|
+
|
|
|
+ A single backtick in a code span: `` ` ``
|
|
|
+
|
|
|
+ A backtick-delimited string in a code span: `` `foo` ``
|
|
|
+
|
|
|
+will produce:
|
|
|
+
|
|
|
+ <p>A single backtick in a code span: <code>`</code></p>
|
|
|
+
|
|
|
+ <p>A backtick-delimited string in a code span: <code>`foo`</code></p>
|
|
|
+
|
|
|
+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:
|
|
|
+
|
|
|
+ Please don't use any `<blink>` tags.
|
|
|
+
|
|
|
+into:
|
|
|
+
|
|
|
+ <p>Please don't use any <code><blink></code> tags.</p>
|
|
|
+
|
|
|
+You can write this:
|
|
|
+
|
|
|
+ `—` is the decimal-encoded equivalent of `—`.
|
|
|
+
|
|
|
+to produce:
|
|
|
+
|
|
|
+ <p><code>&#8212;</code> is the decimal-encoded
|
|
|
+ equivalent of <code>&mdash;</code>.</p>
|
|
|
+
|
|
|
+
|
|
|
+
|
|
|
+<h3 id="img">Images</h3>
|
|
|
+
|
|
|
+Admittedly, it's fairly difficult to devise a "natural" syntax for
|
|
|
+placing images into a plain text document format.
|
|
|
+
|
|
|
+Markdown uses an image syntax that is intended to resemble the syntax
|
|
|
+for links, allowing for two styles: *inline* and *reference*.
|
|
|
+
|
|
|
+Inline image syntax looks like this:
|
|
|
+
|
|
|
+ 
|
|
|
+
|
|
|
+ 
|
|
|
+
|
|
|
+That is:
|
|
|
+
|
|
|
+* An exclamation mark: `!`;
|
|
|
+* followed by a set of square brackets, containing the `alt`
|
|
|
+ attribute text for the image;
|
|
|
+* followed by a set of parentheses, containing the URL or path to
|
|
|
+ the image, and an optional `title` attribute enclosed in double
|
|
|
+ or single quotes.
|
|
|
+
|
|
|
+Reference-style image syntax looks like this:
|
|
|
+
|
|
|
+ ![Alt text][id]
|
|
|
+
|
|
|
+Where "id" is the name of a defined image reference. Image references
|
|
|
+are defined using syntax identical to link references:
|
|
|
+
|
|
|
+ [id]: url/to/image "Optional title attribute"
|
|
|
+
|
|
|
+As of this writing, Markdown has no syntax for specifying the
|
|
|
+dimensions of an image; if this is important to you, you can simply
|
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+use regular HTML `<img>` tags.
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+
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+
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+* * *
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+
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+
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+<h2 id="misc">Miscellaneous</h2>
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+
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+<h3 id="autolink">Automatic Links</h3>
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+
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+Markdown supports a shortcut style for creating "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:
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+
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+ <http://example.com/>
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+
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+Markdown will turn this into:
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+
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+ <a href="http://example.com/">http://example.com/</a>
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+
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+Automatic links for email addresses work similarly, except that
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+Markdown will also perform a bit of randomized decimal and hex
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+entity-encoding to help obscure your address from address-harvesting
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+spambots. For example, Markdown will turn this:
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+
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+ <address@example.com>
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+
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+into something like this:
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+
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+ <a href="mailto:addre
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+ ss@example.co
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+ m">address@exa
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+ mple.com</a>
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+
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+which will render in a browser as a clickable link to "address@example.com".
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+
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+(This sort of entity-encoding trick will indeed fool many, if not
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+most, address-harvesting bots, but it definitely won't fool all of
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+them. It's better than nothing, but an address published in this way
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+will probably eventually start receiving spam.)
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+
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+
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+
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+<h3 id="backslash">Backslash Escapes</h3>
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+
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+Markdown allows you to use backslash escapes to generate literal
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+characters which would otherwise have special meaning in Markdown's
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+formatting syntax. For example, if you wanted to surround a word
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+with literal asterisks (instead of an HTML `<em>` tag), you can use
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+backslashes before the asterisks, like this:
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+
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+ \*literal asterisks\*
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+
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+Markdown provides backslash escapes for the following characters:
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+
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+ \ backslash
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+ ` backtick
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+ * asterisk
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+ _ underscore
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+ {} curly braces
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+ [] square brackets
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+ () parentheses
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+ # hash mark
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+ + plus sign
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+ - minus sign (hyphen)
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+ . dot
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+ ! exclamation mark
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