What is Wordpress' custom post type 'Logs'?

Question

I'm in index.php and I'm trying to create a list of links to the archive pages for three custom post types I've registered. Here's what I have so far:

// Get custom post types, excluding Wordpress' built-in ones

$cpts = get_post_types( array(
    '_builtin' => false
));

// Get a name and a link to the archive page of each custom post type

foreach( $cpts as $cpt ) {
    $name = get_post_type_object( $cpt )->labels->name; 
    $link = get_post_type_archive_link( $cpt );
    echo "<a href=$link>$name</a>";
}       

The code works well except that, in addition to the three custom post types I've registered, a fourth one comes up whose $name is Logs and the $link is my site's homepage url.

What is this 'Log' post type? Is it Wordpress' default Post? Shouldn't the _builtin => fakse parameter for get_post_types exclude it already? If not, how do I exclude it?

Answer 1

Like mmm suggested in the comments, 'Logs' is a custom post type created by a plugin I'm using, which means that the correct answer is there is no default Wordpress' custom post type. I hope it's clearer now.