How do they book tickets and indicate that they want to come?
This can only be done online. However, this won’t be available until the invitations have been sent out in mid September. They should register whatever their decision i.e. even if they are attending by themselves without guests or do not wish to attend. If not they will either not be included in the ceremony or the dispatch of their certificate afterwards will be delayed. They should not wait for their results before booking their attendance and any tickets required but must do this by the deadline of Monday 26 October indicated below.