For context, direct link to NASDAQ rule 4626:

http://nasdaq.cchwallstreet.com/nasdaq/main/nasdaq-equityrul...

EDIT: Also, "NASDAQ Equity Trader Alert #2012-21: NASDAQ Proposes Policy for Unfilled Orders in the Facebook Inc. (FB) IPO Cross":

http://www.nasdaqtrader.com/TraderNews.aspx?id=ETA2012-21

(Their website fails to work in Chrome if you click around -- alert bubble states only IE and Firefox are supported. Tsk tsk.)