The USERNAME field of the CANCELLED table lists the user who created the reservation. There is no way to tell who actually cancelled the reservation. It would be useful to rename the USERNAME field to e.g. USERNAME_REQUEST and add a field for the username of the person who cancelled the reservation, e.g. USERNAME_CANCEL.
Scenario: A user reserves a room and gets an email notification which is used as proof of the reservation. The room reservation is subsequently cancelled (either deliberately or inadvertently). A different user then reserves the room and gets an email notification as proof of the reservation. Both users show up in the library with their emails claiming to have reserved the room for the same time period. Per the OpenRoom interface, we can tell who has the "legitimate" reservation. However, in trying to sort this out, there is no way to tell who cancelled the original reservation, since both the original requester or any administrative user can cancel a reservation.
Note that I have verified that the CANCELLED.USERNAME value is the person who made the original reservation request, not the person who cancelled the request.
The icing on the cake for this enhancement request would be to be able to look up who cancelled a reservation in the Reports interface vs having to query the CANCELLED table.
-- Michael Doran, University of Texas at Arlington