You will get a letter with options on how many (up to a max of...

You will get a letter with options on how many (up to a max of pro-rata based on your current holdings. You can apply to take up all the extra shares, or a smaller number. After the applications are processed, depending on how many have been applyed for they will average it out across all applicants.

So you don't lose anything, although your shares may be diluted in value only slightly. If you apply and get an allocation they appear in your holdings when issue.

Advantage is no brokerage fees, so a small number applied for doesn't get wiped out by the brokerage. (although there may be a minimum)