post_modified_gmt, $post->post_date_gmt );

		if ( $modified !== '0000-00-00 00:00:00' ) {
			$url['mod'] = $modified;
		}

		$url['chf'] = 'daily'; // Deprecated, kept for backwards data compat. R.

		$canonical = WPSEO_Meta::get_value( 'canonical', $post->ID );

		if ( $canonical !== '' && $canonical !== $url['loc'] ) {
			/*
			 * Let's assume that if a canonical is set for this page and it's different from
			 * the URL of this post, that page is either already in the XML sitemap OR is on
			 * an external site, either way, we shouldn't include it here.
			 */
			return false;
		}
		unset( $canonical );

		$url['pri'] = 1; // Deprecated, kept for backwards data compat. R.

		if ( $this->include_images ) {
			$url['images'] = $this->get_image_parser()->get_images( $post );
		}

		return $url;
	}
}