With the release of Self Checkin and eSign, it is possible to send your Guests to https://mybooking.bookingcenter.com with an RUID reference (a 'secure' URL) and the guest can view, cancel, update their details, eSign documents, and make changes to their bookings.  

When any activity occurs on that web service, the Log entry on the booking will reference "mybooking", meaning someone was provided the RUID to access their booking online, and did something to be logged.  Since we don't know for sure who the Guest was, we Log it as "mybooking".

Properties do not have to use the "mybooking" web service. The only way a guest can access that area is to have the RUID, which would be sent via a Letter as an email or SMS.  An RUID to a booking should not be used if you don't have a way to manage the area properly with clear business rules, as guests can interact with their bookings via that secure link.

Learn more about mybookings here.