From the T&C's:
<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Customers without Star Alliance airline frequent flyer programme membership but with status in a non-Star Alliance frequent flyer programme must register, enrol into one Star Alliance member airline frequent flyer programme, provide their new membership number and provide proof of status in their non-Star Alliance frequent flyer programme (by electronic e-mail of the last statement or complete form available, sent to the fax number provided). The frequent flyer statement or e-statement must be no more than three months old prior to registration date of this promotion. </font>
So, what's to stop me getting my last email statement, editing it in Word to say I've got Gold on BA, then faxing it to *A and getting comped Gold on my UA programme???
Answers on a postcard please... ;-)
Regards
PhilH