The "/alerts" page:

Edit email alert and notification settings.

The subscriber is identified in several ways:

   (1)  The name= query parameter contains the complete subscriberCode.
        This only happens when the user receives a verification
        email and clicks on the link in the email.  When a
        compilete subscriberCode is seen on the name= query parameter,
        that constitutes verification of the email address.

   (2)  The sid= query parameter contains an integer subscriberId.
        This only works for the administrator.  It allows the
        administrator to edit any subscription.
        
   (3)  The user is logged into an account other than "nobody" or
        "anonymous".  In that case the notification settings
        associated with that account can be edited without needing
        to know the subscriber code.

   (4)  The name= query parameter contains a 32-digit prefix of
        subscriber code.  (Subscriber codes are normally 64 hex digits
        in length.) This uniquely identifies the subscriber without
        revealing the complete subscriber code, and hence without
        verifying the email address.