WordPress at a glance
filter is not described

wp_get_comment_fields_max_lengths filter-hook . WP 4.5.0

Filters the lengths for the comment form fields.

Usage

add_filter( 'wp_get_comment_fields_max_lengths', 'filter_function_name_5' );
function filter_function_name_5( $lengths ){
	// filter...

	return $lengths;
}
$lengths(array)
Associative array 'field_name' => 'maximum length'.

Where the hook is called

wp_get_comment_fields_max_lengths()
wp-includes/comment.php 1132
return apply_filters( 'wp_get_comment_fields_max_lengths', $lengths );

Where the hook is used (in WP core)

Does not used.