Source

File: wp-includes/link-template.php

function get_previous_posts_link( $label = null ) {
	global $paged;

	if ( null === $label ) {
		$label = __( '« Previous Page' );
	}

	if ( ! is_single() && $paged > 1 ) {
		/**
		 * Filters the anchor tag attributes for the previous posts page link.
		 *
		 * @since 2.7.0
		 *
		 * @param string $attributes Attributes for the anchor tag.
		 */
		$attr = apply_filters( 'previous_posts_link_attributes', '' );
		return '<a href="' . previous_posts( false ) . "\" $attr>" . preg_replace( '/&([^#])(?![a-z]{1,8};)/i', '&#038;$1', $label ) . '</a>';
	}
}