Kris, the reason why it IS ok to put in a link and NOT ok to the link in url brackets so that the pic shows is because if the pic is put in url brackets a) it steals bandwidth from that site, b) it can (somehow) cause problems to this site.
Let's get this right Ben or it will cause more confusion. It's perfectly OK to put a link in URL brackets like this:
http://www.simviation.com/lair/photos/da-hind01.jpgThe problem arises when using a direct link to an image hosted on another site & posting it so it displays in the topic like this:
Note that both the above images are my own photos posted at my Lair which is hosted by Simviation. In this case I'm hoping the situation does not arise.I don't visit Anet much so I'm not aware of their rules. I suspect the reason they & similar sites give a convenient direct link to the pages the photos are posted on is to prevent people downloading the images & posting them on forums as Paul suggested. They are all high-resolution images so even the smaller ones are probably outside the forum limits & therefore need editing to upload here. By being posted at Anet the images are copyrighted to the original photographer & they quite naturally object to people doing this sort of thing. I see no objection to downloading the photo for your own use or to look at when you're offline as long as no profit is made from it. This is very similar to the rules on any freeware files.
PS. The above image is way above the file size limit for this forum which explains one reason this is discouraged. It cannot be removed without editing this post, another very good reason. It might also take some time to detect a remote host & load the image which affects the time taken for the page to load. The whole idea is for this forum to function as smoothly as possible.