WordPress at a glance
filter is not described

get_the_generator_(type) filter-hook . WP 2.5.0

Filters the HTML for the retrieved generator type.

The dynamic portion of the hook name, $type, refers to the generator type.

Usage

add_filter( 'get_the_generator_(type)', 'filter_function_name_633', 10, 2 );
function filter_function_name_633( $gen, $type ){
	// filter...

	return $gen;
}
$gen(string)
The HTML markup output to wp_head().
$type(string)
The type of generator. Accepts 'html', 'xhtml', 'atom', 'rss2', 'rdf', 'comment', 'export'.

Where the hook is called

get_the_generator()
wp-includes/general-template.php 4177
return apply_filters( "get_the_generator_{$type}", $gen, $type );

Where the hook is used (in WP core)

Does not used.