C. Johnson

Footnotes for WordPress is a simple plugin designed with a simple aim in mind: to make 
it dead-easy to include decently-formatted footnotes in posts and pages on your 
WordPress blog.
The syntax is roughly based on the common MediaWiki syntax for footnotes, but uses the 
WordPress shortcode conventions. So, to include a footnote with the text “Text,” you use:
<pre><code>This is footnoted.[ref]Text[/ref]
</code></pre>
And that’s all you need to do. When you add a footnote, Footnotes for WordPress will 
create a note marker at the point that the foonote appears in the text, and includes 
the text of the footnote in a styled list of notes down the page. When a reader clicks 
on the link in a JavaScript-enabled browser, a script included with the plugin will 
create a small bubble inline in the text, which pops up over the footnote marker for 
easy reading without losing their place. In non-JavaScript-enabled contexts, clicking 
on the footnote marker jumps down the page to the text of the note.
The jump is based on an unique anchor which the plugin can automatically generate for 
you. However, if you want to create a specific ID of your own for the footnote, you 
can do so using the <code>name="..."</code> attribute:
<pre><code>This is footnoted.[ref name="my-unique-id-1"]Text[/ref]
</code></pre>
If you define an ID for a footnote, you can also refer back to the same footnote 
later on in the document, using the <code>[backref name="..."]</code> shortcode.
<pre><code>This is footnoted.[ref name="source1"]Source 1[/ref]

So is this.[ref name="source2"]Source[/ref]

And this one comes from the same source as the first.[backref name="source1"]
</code></pre>
Footnotes are numbered, beginning at 1. However, you can change the numbering if you 
so desire using the <code>number="..."</code> attribute. For example, I often use this when 
quoting from a book that contains footnotes or endnotes, in order to represent the 
notes used by the original text.
<pre><code>This is footnoted, but footnotes begin at number 42.[ref number="42"]...[/ref]
</code></pre>
You can change the text that is displayed in the note’s superscripted link from the 
note’s number to any text or symbol that you choose using the <code>superscript="..."</code> 
attribute. For example, to use an asterisk instead of the note number:
<pre><code>This is footnoted with a good old asterisk.[ref superscript="*"]...[/ref]
</code></pre>
By default, the list of footnotes appears at the bottom of the post. However, if you 
wish them to appear somewhere above the bottom of the post, for formatting or other 
reasons, you can do so using the <code>[references/]</code> shortcode:
<pre><code>This is footnoted.[ref]Text[/ref]

As are some[ref]Text[/ref] other things.

[references/]

See also: Endnotes.
</code></pre>
Which will cause the two footnotes to appear beneath the second paragraph but above 
the “See also:” text.
<h3>Usage</h3>
<ul>
<li>
To create a footnote, use <code>[ref]...[/ref]</code> to wrap the text of your note.
Example: <code>This is footnoted.[ref]This is the text of the of the footnote.[/ref]</code>
</li>
<li>
Normally footnotes use numbered superscripts to indicate the footnote, beginning 
with 1. You can choose to use symbols instead, like *, **, †, etc. To use custom 
text for a footnote’s superscript, use <code>[ref superscript="*"]...[/ref]</code>, and 
replace the asterisk with whatever symbol or text you want to use.
</li>
<li>
Normally footnotes begin at 1 and count up towards infinity. If you want to use 
numbered subscripts but need to reset the number they count from, use the <code>number</code> 
attribute. For example, if you want the current subscript to be numbered 128, and 
for subsequent subscripts to be numbered 129, 130, etc., use: 
 [ref number=”128″]…[/ref].
</li>
<li>
To create a footnote with a specific unique ID, instead of the one that the plugin 
will automatically generate for you, use <code>[ref name="..."]...[/ref]</code>
Example: <code>This is footnoted.[ref name="my-unique-id"]This is the note text.[/ref]</code>
</li>
<li>
If you define an ID for a footnote, you can also refer back to the same 
footnote later on in the document, using the <code>[backref name="..."]</code> 
shortcode.
This is footnoted.[ref name=”source1″]Source 1[/ref]
So is this.[ref name=”source2″]Source[/ref]
And this one comes from the same source as the first.[backref name=”source1″]
</li>
<li>
To force the plugin to display notes at a different location instead of at the bottom 
of the post, use <code>[references/]</code>
Example:
This is footnoted.[ref]Text[/ref]
As are some[ref]Text[/ref] other things.
[references/]
See also: Endnotes.
</li>
<li>
If you wish to change how footnotes are styled, you can alter them in your 
WordPress theme stylesheet, or using JavaScript. The default elements and 
classes are <code><a class="footnoted"></code> for superscript links to footnotes,
</li>
</ul>
<
ol class=”footnotes”> for the list of references, and
<li> for each individual footnote. So, for example, to 
 display footnotes at the bottom in a simple list, rather than in individual 
 boxes with “Note” headers, add the following line to your Theme stylesheet:</li>

<pre><code> ol.footnotes li {
 background: transparent !important;
 padding: 0px !important;
 border: none !important;
 margin: 0.5em 2em !important;
 }

The use of `!important` will ensure that it overrides the default styles
set up by the plugin.
</code></pre>
<ul>
<li>
Alternatively, if you want to change the CSS class which is applied to to 
the footnotes list, you can do so using the <code>class</code> parameter on 
 [references/]:
<pre><code>This is a test.[ref]Lewis (2000).[/ref]

<h3>Notes</h3>

[references class="compact" /]
</code></pre>
… which will produce the following HTML:
<pre><code>This is a test.[<a href="#test-n-1" class="footnoted"
id="to-test-n-1">1</a>]

<h3>Notes</h3>
<ol class="compact">
<li class="footnote" id="test-n-1">[1] Lewis
(2000). <a class="note-return" href="#to-test-n-1">↩</a></li
></ol>
</code></pre>
Since the default styling is based on children of <code>ol.footnotes</code>, those 
styles will not apply, and you can apply whatever styles you wish to the 
class that you’ve created.
<h3>Changes from version 2010.0309 to version 2010.0822</h3>
</li>
<li>
Added <code>[backref name="..." /]</code> shortcode allowing you to refer back to a note with an established name
</li>
<li>
Eliminated a bug which caused duplicate IDs if you tried to set up multiple sections of footnotes in the same post using repeated <code>[references/]</code> codes.
</li>
<li>
Added <code>[references class="foo" /]</code> syntax, allowing user to supply their own class for CSS re-styling purposes.
</li>
<li>
Tested for and verified compatibility up to WordPress 3.0.1 and WordPress trunk.
</li>
</ul>
<h3>Changes from version 2010.0306 to version 2010.0309</h3>
<ul>
<li>Eliminates a harmless but potentially annoying source of “Missing argument” warnings from PHP</li>
</ul>

Footnotes for WordPress

Footnotes for WordPress enables easy-to-use fancy footnotes for WordPress posts.

AS OF MAY 2016, THIS PLUGIN IS NOT BEING MAINTAINED AND WILL NOT RECEIVE ANY FUTURE UPDATES. 
CONTACT ME IF YOU’D LIKE TO LIST AN ALTERNATIVE HERE.
Alternatives: 
– https://wordpress.org/plugins/footnotation/
This plugin provides an extremely easy way to add elegant looking footnotes to 
your posts. The syntax is natural, simple to understand, and degrades 
gracefully if the plugin is removed. Footnotes are linked unobtrusively and the 
note itself links back to the original text where the footnote is referenced.
Adding footnotes to a post is simple. Just type them inline in your post in 
square brackets like this:
<pre><code> [1. This is a footnote.]
</code></pre>
Each footnote must have a number followed by a period and a space and then the 
actual footnote. They don’t have to be unique but it is recommended. It doesn’t 
matter what the numbers are since the footnotes will be automatically 
renumbered when the post is displayed.
Footnotes can contain anything you’d like including links, images, etc. 
Footnotes are automatically linked back to the spot in the text where the note 
was made.
<h4>Settings</h4>
Only show footnotes on single post/page: This option will hide 
footnotes on the main blog page. Footnote numbers will still appear 
but link to the individual post/page URL.
Collapse footnotes until clicked: When checked, footnotes are 
hidden until manually expanded or a footnote number is clicked.
Note: Do not include square brackets [] inside the footnotes themselves.
Note: Footnote numbers don’t need to be unique but it is recommended, 
especially if the text is identical for multiple footnotes. If you have 
multiple footnotes with the exact same text and number then you’ll get weird 
and incorrect footnotes on your post.

FD Footnotes Plugin

Add elegant looking footnotes to your posts simply and naturally.

Footnotes for WordPress vs FD Footnotes Plugin