@NogDogApr 28.2009 — #If you are asking how to know from within PHP what headers the web server is going to send if you do not override them, I do not know of any built-in way to do that other than to request a file from your server via cURL and see what the headers are.
But ultimately, why should you care? Just set the headers you want to use and then you don't have to worry about it.