In addition to the catalog there is a supplementary file, exclude.lis which contains the number of the lune bins that are excluded (see Strauss et al. 1992, ApJS, 83, 29 for a full description). There is a series of Fortran programs in exclude.f that should be used to decide if a given object is in the excluded regions or not. First, run the program write_lmask, which reads the exclude.lis file and creates a binary file lmask.lis, which has much faster I/O. This only need be done once. Your code will need to call init_lmask to read in lmask.lis, and thereafter call the logical function exclude to decide if an object is in the excluded zones or not.