Table VIII (TN85)
Blank Areas of Sky for Flat Fields 

 BLANK1      04 25 46.0   +54 09 03    B1950
 BLANK2      13 04 33.0   +29 50 49    B1950
 BLANK3      16 47 52.5   -15 17 44    B1950
 BLANK4      19 19 09.0   +12 22 05    B1950
 BLANK5      21 26 54.4   -08 51 41    B1950
 BLANK6      23 54 08.9   +59 28 18    B1950
Fields having a paucity of bright stars. Useful for flat fields especially if the sky is dark.

Reference : Christian, C.A., et al. 1985. P.A.S.P., 97, 363 and Users' Manual for the CCD Camera on the 0.9m telescope, KPNO.