Before I wrote about bug in stringByAddingPercentEscapesUsingEncoding.
A log still says that there are some people who visit my site from a MacRumors forum.
So, I would like to clarify what was misunderstood and how to solve the issue.
I found out that it was not a bug. The document didn’t mention about its purpose clearly. That’s it.
The stringByAddingPercentEscapeUsingEncoding is for making a URL. In URL, as it was written in its comment posts, & is reserved for passing parameters in HTTP protocol. So, if & and other special characters used in your XML or HTML element, you need to change them to these.
So, if those special characters are inbetween HTML/XML tags, convert it. Then you will not have any problem.