I would like to add a comment about IBM Redbooks, in particular when you noticed either via the weekly IBM Redbooks newsletter or by browsing the IBM Redbooks website (ibm.com/redbooks) that a particular publication has been updated.
Minor publication updates will still show as "This publication has been updated." However, minor updates mean that commands, sentences, or any small sections have been updated from comments received from the readers. Unless specified, the update does not mean that the book has been updated from the version deployed and tested during the residency to the current version. For example, the IBM PowerHA SystemMirror Standard Edition 7.1.1 for AIX Update, SG24-8030 (http://www.redbooks.ibm.com/abstracts/sg248030.html?Open) although the website shows "Last Update 23 July 2014", the publication version remains the same.
Have a great rest of the day.