I notice that some links in messages on Psych Central lead directly to the page linked, replacing the P.C. page, while others open a new browser window in addition to the P.C. one. Looking at the Source code shows the difference in HTML coding, but I don't see how to do that from the usual Reply window (Instant UBB Code). Is there a way?

Here is an example of a link which opens a new page:

Fight AIDS

and here is one which does not open a new page:

Healing Through Books: Bibliotherapy

I guess you will have to look at the Source to see how these differ in coding!