README FOR FIRST APM catalogue 

Size
3.6 Mbytes compressed (11.6 Mbytes uncompressed) and contains
85611 sources.  


- For upper limits on E or O, the plate limit (with the photometry
  calibration applied) is given as a negative magnitude.  For these
  objects the class and psf values are set to 0

- include matches out to 5 arcsec.

- the color for objects with upper limits is always -9.99.