The plate catalogue is available via anonymous ftp to ftp.roe.ac.uk. A running number for all UKST plates.
G indicates an objective grating was fitted.
M indicates multiple images. T indicates the exposure was tracked eg for a comet. Only the target image will be stationary other images will be trailed. An entry here indicates that the plate was taken for one of the UKST Sky Surveys. Equinox 1950 coordinates of the plate centre.