Is it advisable to Enable => Trackback,Pingback,Refback

Is it advisable to Enable => Trackback,Pingback,Refback

in my forums

i see this :
vBulletin SEO Forums - LinkBacks

But did not understand something

I need my site to be good for Search engine

I suggest enabling them, but leaving them all moderated. It's nice for staff/admin to be able to see who's linking in, but having a bunch of 'free' links out on your site is probably not advisable.

Yes, enable them, especially if you have more than one website landing on your forum.

If you market your forums to other sites, trackbacks shows it.

Keep it moderated, to prevent spam trackbacks such as those medicine websites.

If you have time to moderate them , you should enable linkbacks, Otherwise keeping that turned off is a good option.

My process is to leave them moderated. I occasionally scan them in the threads I'm visiting. When I find unsuitable (or spam) links, I delete them.

However, when I find a highly targeted link that may be of value to those reading the thread, I like to approve it for public view.