This asks a series of questions about what grating is in each camera and the grating angle. These questions must be answered for each camera in use. Otherwise, the subsequent headers will not have the correct grating angles. A number of suggested values for various situations are typed out. The image scale is only used in calculations of seeing, so it is not critical that it be absolutely correct.
Most observers have their own system of night numbers.
This word allows you to set the frame counter, which determines the name of the image, to an arbitrary value. You can repeat this for several pairs of stars if desired without redisplaying the frame. This is in fact always the case in all Palomar instruments that use CCD detectors in order to minimize the effects of charge transfer on spectral resolution.