Does WWW has cache? Any official member can give us a result?

The simplest code like this: WWW www = new WWW("http://10.0.0.7/aaa"); yield return www;

I want to know with the code like above, every time I run this code, can I get newest content from server?

I had a test, to get content first, then modify content on server in 5 seconds and get it again, I can get the modified content, this is what I expected. But I still can't make sure there's no cache, because I searched this topic, someone has this problem.

Any official member can give us a result? How WWW works inside?

Sometime, to use WWW is the easiest way to access web server, if there's no a definite answer, I have to use HttpWebRequest and handle everything by my own.