: The URL-encoded equivalent of :// . Specifically: %3A (or 3A ) = : (colon) %2F (or 2F ) = / (forward slash) Common Use Cases
Allowing a proxy to handle file:/// links creates several critical risks: proxy-url-file-3A-2F-2F-2F
Therefore, proxy-url-file:/// likely means: “Access a local file, but route the request through a proxy handler named ‘proxy-url-file’.” : The URL-encoded equivalent of ://
proxy-url-file%3A%2F%2F%2F