wp-includes/rewrite.php 1010. satır civarı

        if (empty($this->category_base))
            $this->category_structure = trailingslashit( $this->front . '' );
        else
            $this->category_structure = trailingslashit( '/' . $this->root . $this->category_base );
        $this->category_structure .= '%category%.html';
        return $this->category_structure;

wp-includes/category.php 114. satır civarı

$full_path .= ( $pathdir != '' ? '.html' : '' ) . sanitize_title( $pathdir );

sonuç:
http://localhost/wordpress/deneme-1.html
http://localhost/wordpress/kategorisiz.html
zor başarılır, imkansız zaman ister