Spectral resolution is set by the VLBI correlator. With the VLBA correlator each BB channel can be divided into 32, 64, 128, 256, 512, or 1024 spectral points, subject to the limitations specified in Section 8. The spectral resolution is the bandwidth per BB channel divided by the number of spectral points. The VLBA correlator can apply an arbitrary special smoothing, which will affect the statistical independence of these points and thus the effective spectral resolution. Typical continuum programs request averaging to 16 spectral points, although this limits the ability to image parts of the field away from the correlator phase center (see Section 13). The limits on spectral resolution will be eliminated when the DiFX correlator becomes operational in 2009.