WordPress at a glance
filter is not described

comments_link_feed filter-hook . WP 3.6.0

Filters the comments permalink for the current post.

Usage

add_filter( 'comments_link_feed', 'filter_function_name_2047' );
function filter_function_name_2047( $comment_permalink ){
	// filter...

	return $comment_permalink;
}
$comment_permalink(string)
The current comment permalink with '#comments' appended.

Where the hook is called

comments_link_feed()
comments_link_feed
wp-includes/feed.php 263
echo esc_url( apply_filters( 'comments_link_feed', get_comments_link() ) );

Where the hook is used (in WP core)

Does not used.