In your fragment proxy-url-file-3A-2F-2F-2F , the problem is that the instead. How does this happen in real software systems?
To understand what this "feature" represents, you have to decode the syntax: proxy-url-file-3A-2F-2F-2F
: Organizations often use a PAC file to tell employee browsers how to route traffic. While these are often hosted at a web URL (e.g., http:// ), a developer might use file:/// to test a local version of that script before deploying it. In your fragment proxy-url-file-3A-2F-2F-2F , the problem is