The HFM UI has been tested in accordance with the software accessibility standards required by the US Federal Rehabilitation Act (Section 508).Besides mentioning this accessibility feature the rest of the readme is stuffed with fixed defects (41 in total!). One of the most important corrections is that the web form performance fixes already released for HFM 220.127.116.11 have now been brought over to 18.104.22.168 as well. For the rest of the list please see the readme file on Oracle Support.
Note that this PSU requires three patches to Oracle common components: ADF patch 16788543 and two general Fusion Middleware patches: 13866584 and 16810628. Make sure you get the correct version (111170_Generic) of these packages when downloading them from Support.
Update: There are quite a few PSUs released for other products as well. See the Oracle Business Analytics Proactive Support blog for the lengthy list: October EPM patch set updates released.