External links should open in a new tab (BBCode).

[shakesoda]

Currently external links on the forum just open in the same tab, and it's annoying.

[SoonDead]

It would be very easy to implement this using only javascript, like:

var regex = new RegExp('/' + window.location.host + '/');
$('.usercontent a').each(function () {
    if (!regex.test(this.href)) {
        this.target = '_blank';
        $(this).addClass('external');
    }
});

(I just mocked this up now, so no guarantees) Doing this server side might be more appropriate, but if this javascript suffices I could test and push it today.

[shakesoda]

I feel like a server-side solution is more appropriate for this. Adding target="_blank" to all links in SMBBCodeParser is trivial, but really just external ones should have it (granted, the vast majority of links will be).