JDBC connection

[Winla]

The 3 parts JDBC connection syntax are

jdbc:<subprotocol>:<subname>

and from a sun java lesson, I get following

Supposing that "dbnet" is a protocol for connecting to
a host on the Internet, a JDBC URL might look like this:

jdbc:dbnet://wombat:356/fred


Question:

1)what is "dbnet" protocol?

2) can I write like this?

jdbc:dbnet://www.mysite.com:1234/myDBname


Thanks for help.