Submit a link to Digg: Invalid URL

Question

I am trying to submit an URL to Digg, but get Invalid URL:

What's the problem?

Answer 1

Add index.html¹ to the end of your URL and then Digg should accept your submission, it worked for me.

¹ or index.htm, or index.asp, or default.htm, or whatever the webserver uses for the default document

Answer 2

The problem is that Digg does not accept server-only URLs.

The unit at Digg is stories, not websites.
They have a filter that tries to detect whether an URL is a story or not.

So instead of server.com, I submitted server.com/article.html and it worked: