there are lots of topics about this, basically
It is not valid xhtml strict to use target="_blank"
It is not desirable to force the user to open the link in a new window, if they want to open it in a new window, they can by middle or right click
ok it was just an example....
i think it is. a user who reads a thread usually dont want to leave the messages and then always go back to messages after finished browsing the site the link was pointing to.
and it is annoying to always right click - open link in new tab...
phpbb,vbulletin,ipb etc opens them in new window, punbb is the first one i met that opens them in the same window. couldn't i be right?