WordPress at a glance
filter is not described

comment_moderation_subject filter-hook . WP 1.5.2

Filters the comment moderation email subject.

Usage

add_filter( 'comment_moderation_subject', 'filter_function_name_3031', 10, 2 );
function filter_function_name_3031( $subject, $comment_id ){
	// filter...

	return $subject;
}
$subject(string)
Subject of the comment moderation email.
$comment_id(int)
Comment ID.

Where the hook is called

wp_notify_moderator()
wp-includes/pluggable.php 1722
$subject = apply_filters( 'comment_moderation_subject', $subject, $comment_id );

Where the hook is used (in WP core)

Does not used.