Often, administrative users will need to create bookings on behalf of other users. To do this, they can wear the "mask" of the user for a period of time, allowing them to make the bookings as required.
To put on the mask, select first the "Masqeurade" option from the Bumblebee menu. Then select the user you wish to masquerade as from the list of users given to you. That you are wearing a mask will be shown on the Bumblebee menu so that you don't forget.
You can then make bookings as per usual, except that the booking will be made in the name of your mask. Note that the your name is also recorded as having made that booking.
To take off the mask, either click on "end" on the masquerade warning on the Bumblebee menu or go back to "Masquerade" and select "Remove mask".