Of course it depends on the protocol and/or application. That's the way it is meant to be and why they will be useful for a long time. However, a popular conve

Of course it depends on the protocol and/or application. That's the way it is meant to be and why they will be useful for a long time. However, a popular convention is to use protocol://[username[:password]@]host[:port]/path/components/separated/by/slashes?with=query&params=like&this and in practice many URL schemes use this format or a subset of it.