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function is not described

ms_file_constants() WP 3.0.0

Defines Multisite file constants.

Exists for backward compatibility with legacy file-serving through wp-includes/ms-files.php (wp-content/blogs.php in MU).

No Hooks.

Return

Nothing (null).

Usage

ms_file_constants();

Code of ms file constants: wp-includes/ms-default-constants.php WP 5.2.2

<?php
function ms_file_constants() {
	/**
	 * Optional support for X-Sendfile header
	 *
	 * @since 3.0.0
	 */
	if ( ! defined( 'WPMU_SENDFILE' ) ) {
		define( 'WPMU_SENDFILE', false );
	}

	/**
	 * Optional support for X-Accel-Redirect header
	 *
	 * @since 3.0.0
	 */
	if ( ! defined( 'WPMU_ACCEL_REDIRECT' ) ) {
		define( 'WPMU_ACCEL_REDIRECT', false );
	}
}