The simplelink WiFi programmers guide was updated this month, August 2015.
The updated document is containing different editorial corrections collected in the past year, as well as new information on numerous items such as: "Configurable Info Element", Error codes and more.
The document can be found at: http://processors.wiki.ti.com/index.php/CC31xx_Programmers_Guide
You can verify that you are using the updated document by checking the cover page:
