code4

This is the long description. No limit, and you can use Markdown (as well as in the following sections).
For backwards compatibility, if this section is missing, the full length of the short description will be used, and 
Markdown parsed.
A few notes about the sections above:
<ul>
<li>“Contributors” is a comma separated list of wp.org/wp-plugins.org usernames</li>
<li>“Tags” is a comma separated list of tags that apply to the plugin</li>
<li>“Requires at least” is the lowest version that the plugin will work on</li>
<li>“Tested up to” is the highest version that you’ve successfully used to test the plugin. Note that it might work on 
higher versions… this is just the highest one you’ve verified.</li>
<li>
Stable tag should indicate the Subversion “tag” of the latest stable version, or “trunk,” if you use <code>/trunk/</code> for 
stable.
Note that the <code>readme.txt</code> of the stable tag is the one that is considered the defining one for the plugin, so 
if the <code>/trunk/readme.txt</code> file says that the stable tag is <code>4.3</code>, then it is <code>/tags/4.3/readme.txt</code> that’ll be used 
for displaying information about the plugin. In this situation, the only thing considered from the trunk <code>readme.txt</code> 
is the stable tag pointer. Thus, if you develop in trunk, you can update the trunk <code>readme.txt</code> to reflect changes in 
your in-development version, without having that information incorrectly disclosed about the current stable version 
that lacks those changes — as long as the trunk’s <code>readme.txt</code> points to the correct stable tag.
If no stable tag is provided, it is assumed that trunk is stable, but you should specify “trunk” if that’s where 
you put the stable version, in order to eliminate any doubt.
</li>
</ul>
<h3>Arbitrary section</h3>
You may provide arbitrary sections, in the same format as the ones above. This may be of use for extremely complicated 
plugins where more information needs to be conveyed that doesn’t fit into the categories of “description” or 
“installation.” Arbitrary sections will be shown below the built-in sections outlined above.
<h3>A brief Markdown Example</h3>
Ordered list:
<ol>
<li>Some feature</li>
<li>Another feature</li>
<li>Something else about the plugin</li>
</ol>
Unordered list:
<ul>
<li>something</li>
<li>something else</li>
<li>third thing</li>
</ul>
Here’s a link to <a href="https://wordpress.org/" title="Your favorite software" rel="ugc">WordPress</a> and one to <a href="http://daringfireball.net/projects/markdown/syntax" title="Markdown is what the parser uses to process much of the readme file" rel="nofollow ugc">Markdown’s Syntax Documentation</a>. 
Titles are optional, naturally.
Markdown uses email style notation for blockquotes and I’ve been told:
<blockquote>
Asterisks for emphasis. Double it up for strong.
</blockquote>
<pre><code><?php code(); // goes in backticks ?>
</code></pre>

Time Line Graph

This is the long description.  No limit, and you can use Markdown (as well as in the following sections).

Automattic

Donncha O Caoimh (a11n)

This plugin adds a stylesheet or image to your blog’s html source code. When a browser loads that stylesheet or image a cookie is dropped. If that user then leaves a comment the cookie is checked. If it doesn’t exist the comment is marked as spam. 
The plugin can also check how long it took a user to enter a comment. If it’s too fast it’s probably a spam bot. How fast can a legitimate user enter their name, email, web address and enter a well thought out comment?
For the adventurous, add these lines to your .htaccess and it will block spam attempts before they ever get to WordPress. Replace the Xs with the cookie that was set in your browser after viewing your blog. You can also find the cookie value by examining the page source code and looking for “css.php?k=XXXXXXXXXXXXXXXXXXX”. Make sure the lines go above the standard WordPress rules.
<pre><code> RewriteCond %{HTTP_COOKIE} !^.*XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX.*$
 RewriteRule ^wp-comments-post.php - [F,L]
</code></pre>
If you use WordPress MU, replace wp-comments-post.php above with wp-signup.php to block spam signups.
<pre><code> RewriteCond %{HTTP_COOKIE} !^.*XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX.*$
 RewriteRule ^wp-signup.php - [F,L]
</code></pre>

Cookies for Comments

If you don't use any other spam filter plugins, then you can rely on this to stop spam comments for sure!

Must have, if you don't use any other spam filters!

I'd been getting a dozen spams a day on two of my sites. We installed "Stop Spam Comments" on one and "Cookies for Comments" on the other. Both worked perfectly. No more spam. Thanks!



very easy and no more spam!

Sets a cookie on a random URL that is then checked when a comment is posted. If the cookie is missing the comment is marked as spam.

Time Line Graph vs Cookies for Comments