documentation for additional repository URL forms - how-to use non-anonymous FTP?

[G.Wolfe Woodbury]

I've pointed at HTTP repositories, but they have proven unreliable for the
really big packages. (No time out to detect a failed download.)

What sort of URL format is there for FTP?  Can a non-anonymous FTP be specified?
Can someone write a wiki page for the additional repositories URLs?

I'd appreciate it, and so would others.
TIA

--Wolfe