The label on volvo genuine ATF 1161540 specifies use for AW 5 or 6 speed up to year 2010. According to various sources in the internet, this is the same as JWS 3309 or Type T-IV.
For > 2010, my volvo dealer said to use volvo 31256774 fluid. Further cross check 31256774 = WS fluid = Aisin AFW+. According to:
http://www.exedy.com.au/assets/file/..._Datasheet.pdf, it is indeed synthetic.
I believe that Aisin only produces two types of fluids for conventional transmission (other than the CVT), namely T-IV & WS (US market) or AFW & AFW+ (asian and russian market). They may have a different branding in Europe. I've asked Aisin to confirm whether they are the same but it seems that they are beating around the bush not directly answering my question. Maybe for legal & marketing reasons for different parts of the world.