Linking to stuff that you control is okay, because you know and control the contents inside the new window. So your example (terms and conditions created by you) is totally cool.

As described in the article, it is dangerous when the link's destination is not controlled by you. That destination has access to its opener's window and could potentially change the url to eg. a malicious look-alike of your site.

It's a consideration when linking to arbitrary pages, but when you own the destination (and trust that your site has no other security issues) then this becomes a non-issue.