The two techniques I've seen in these circumstance Corasian is...

The two techniques I've seen in these circumstance Corasian is that every shareholder gets a set amount (if they've applied for more than the set amount) ie: 10,000 shares and then any subscriptions in excess of this are scaled back by %. The second is that all applications are scaled back by a % (ie: 50% of what has been applied for).
I favour the first scenario, this helps "unscrew" all the small retail shareholders and has a level of fairness.