The offending string is only there because Python’s urllib has a hard-coded list of schemes which use a hostname component or “netloc”. It’s fine for that list

The offending string is only there because Python’s urllib has a hard-coded list of schemes which use a hostname component or “netloc”. It’s fine for that list to contain known schemes from RFCs. Anything else — including proprietary third party schemes — should just use a heuristic. The list is called uses_netloc and is used to help parse the user@host:port part of https, ftp, etc. domains. It’s this list of schemes that includes the forbidden string itms-services, used for Apple’s proprietary iTunes software. The only code that needs this is urlunsplit and urljoin. If your parsed URL has a netloc then the list isn’t even relevant — if you have a netloc then you are assumed to be in uses_netloc. This all seems like a much more sensible approach than trying to selectively include or exclude naughty strings from the source code, per some corporation’s passive aggressive demands.