Confluence before version 4.0 did mark external links with a little green arrow to the up-right, and a little green arrow for attached files pointing to the lower-right.

I think this was very helpful when managing pages (links), as it was easy to see at a glance where the link was pointing to, internal page link vs external link vs attachment.

With 4.x, these green arrows are gone.

I want to request to bring them back. (If you prefer, make it configurable to turn them on or off).

As this feature was gone without any communication, I mark this request as "bug", not "improvement".