Whether or not the rule should apply to all sub domains.
The time, in seconds, that the browser should remember that a site is only to be accessed using HTTPS.
Whether or not to include on the major browsers' preload list. This directive is not part of the specification, for more information about it, you should check the MDN documentation for the header.
The options to customize the HSTS header value.
See
https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Strict-Transport-Security