If TUBETYPE is 'OPEN', DOMETYPE should contain the type of enclosure that surrounds the telescope. Use 'DOME' for a conventional dome with a slit, or for a turret with a slit of constant width. Use 'ROOF' for a building with a roll-off roof. Use 'NONE' for a roll-off building or any other disappearing enclosure that leaves the telescope unshaded from moonlight. As for TUBETYPE, only the first letter is significant.
If TUBETYPE is 'CLOSED', ignore this field.