Surprisingly, going to http://dk redirects to https://www.penguin.com.au/browse/dk for me. How strange (I've never visited the penguin website before this).

This redirected to https://dk.com for me. Is this my ISP's DNS messing with me?

Firefox will sometimes append .com onto the URL.

What a nasty non-feature. Can this be disabled?

Does not load for me

"dk’s server IP address could not be found."

Another one is http://ai

Perhaps that will work.

This works if you add the trailing .: http://ai.