WordPress at a glance
function is not described

the_permalink_rss() WP 2.3.0

Display the permalink to the post for use in feeds.

Hooks in function
Return

Nothing (null).

Usage

the_permalink_rss();

Code of the permalink rss: wp-includes/feed.php WP 5.2.2

<?php
function the_permalink_rss() {
	/**
	 * Filters the permalink to the post for use in feeds.
	 *
	 * @since 2.3.0
	 *
	 * @param string $post_permalink The current post permalink.
	 */
	echo esc_url( apply_filters( 'the_permalink_rss', get_permalink() ) );
}