Source

File: wp-includes/feed.php

function get_the_title_rss() {
	$title = get_the_title();

	/**
	 * Filters the post title for use in a feed.
	 *
	 * @since 1.2.0
	 *
	 * @param string $title The current post title.
	 */
	return apply_filters( 'the_title_rss', $title );
}