You may have more than one structural subscription per project, each with different criteria. You may provide a name in order to identify them in the future in order to edit or delete them.
Also, each email generated by this subscription will quote the name
you choose, both in the email body and as a header
(X-Launchpad-Subscription), making it easy to filter
your bug mail.
So, please provide a short, descriptive name to help you remember this subscription.