Why do I still find some references to CS6 or CS5.5 in the CC Help?

We’ve made efforts to keep the Help content largely evergreen, without separating content based on versions. For information about the latest release, a product’s What’s New article is the best resource. This article will provide you a synopsis of key new and enhanced features with links to detailed feature 

If you are looking for documentation specific to an older version, you can access the PDF file hosted at a Previous Versions Help archive page. You can find the link to your product’s Help archive page in forum thread "How do I find CS6 Help for my product?".