comment_id_not_found
comment_id_not_found is an action that is fired when a comment is submitted on a post that does not exist. This hook could be used to perform additional actions such as logging the violation, blacklisting the user's IP address, etc. It passes one parameter... the ID of the post (note: this is an ID that does not exist!)
Context:
File: wp-comments-post.php
if ( empty($status->comment_status) ) {
do_action('comment_id_not_found', $comment_post_ID);
exit;
}
This hook is an action which means that it primarily acts as an event trigger, instead of a content filter. This is a semantic difference, but it will help you to remember what this hook does if you use it like this: add_action('comment_id_not_found', 'your_function');