wp_get_nocache_headers() WP 2.8.0

Get the header information to prevent caching.

The several different headers cover the different ways cache prevention is handled by different browsers

Return

Array. The associative array of header names and field values.

Usage

wp_get_nocache_headers();

Code of wp get nocache headers: wp-includes/functions.php ^{WP 5.2.2}

<?php
function wp_get_nocache_headers() {
	$headers = array(
		'Expires'       => 'Wed, 11 Jan 1984 05:00:00 GMT',
		'Cache-Control' => 'no-cache, must-revalidate, max-age=0',
	);

	if ( function_exists( 'apply_filters' ) ) {
		/**
		 * Filters the cache-controlling headers.
		 *
		 * @since 2.8.0
		 *
		 * @see wp_get_nocache_headers()
		 *
		 * @param array $headers {
		 *     Header names and field values.
		 *
		 *     @type string $Expires       Expires header.
		 *     @type string $Cache-Control Cache-Control header.
		 * }
		 */
		$headers = (array) apply_filters( 'nocache_headers', $headers );
	}
	$headers['Last-Modified'] = false;
	return $headers;
}