I have been lurking here probably a year now and never noticed the REF come up in this forum. I just started my PhD and was attending a "how to get published" round-table last week, and it came up. Its a highly relevant variable in your career and I would urge you all who don't know about it to look it up. I will post a few links here about what it is, and a few links to articles debating this contentious mechanic. Are you REF-able?

Wiki: