I’ve found the generator meta tag in my fresh installation of WordPress 2.7 here, there and everywhere:

/* In the HTML header */
<meta name="generator" content="WordPress 2.7" />
 
/* In the RSS feed */
<generator>http://wordpress.org/?v=2.7</generator>
 
/* In the Atom feed */
<generator uri="http://wordpress.org/"
 version="2.7">WordPress</generator>

And the code suggests that there’re even more places where this tag might show up.

How to remove it completely

If you’re doing some security through obscurity you might have googled a little bit and found the solutions that use the following piece of PHP code just unsatisfactory:

remove_action('wp_head', 'wp_generator');

So let’s remove it completely like so:

function rm_generator_filter() { return ''; }
add_filter('the_generator', 'rm_generator_filter');

This will remove the tag everywhere: from the HTML, the RSS and the Atom feed, et cetera.

WordPress’ world of possibilities…

Now I’d like to present another solution that might make sense: What about removing the generator tag almost everywhere but not in case of RDF content? Since RDF is widely used as a format for data mining applications why not show the information to these web robots? You could do this like so:

function rm_generator_filter() { return ''; }
 
if (function_exists('add_filter')) {
  $types = array('html', 'xhtml', 'atom', 'rss2',
                 /*'rdf',*/ 'comment', 'export');
  foreach ($types as $type)
    add_filter('get_the_generator_'.$type, 'rm_generator_filter');
}

What it does is adding a filter for every type but RDF returning just and empty string for the generator meta tag.

Although this doesn’t make much sense from the standpoint of security through obscurity because making the information available in just one place would compromise your security anyway, I just wanted to show that WordPress is flexible enough to do something like this.

Download

You can download the above code packaged in a plugin here. Have a look at the code and checkout the define in line 30: set it to true or false whether you’d like to remove the tag completely or not; the default is to remove it just everywhere.