Data necessary to perform accurate calibration for the VLBA are supplied as part of the correlator output files, and will appear within the Astronomical Image Processing System (AIPS) as extension tables attached to the FITS files. These tables include GC (gain), TY (system temperature), and WX (weather) tables for amplitude calibration, PC (pulse-cal) tables for system phase calibration, and FG (flag) tables for editing. For non-VLBA antennas, some or all of these tables may be missing, since relevant monitor data are not available at the time of correlation. For example, for the HSA, GC and TY information are available for most antennas, except that calibration of the phased VLA requires additional information about the flux density of at least one source. Flag (FG) tables for non-VLBA antennas are absent or only partially complete, lacking information about antenna off-source times. In such cases, the ``flag'' input file that is output by the SCHED software may be very useful for flagging data when antennas are not on source; this file appears to be quite good at predicting the on-source times for the GBT, Arecibo, and Effelsberg, but presently underestimates by about 10 seconds the time it takes for Y27 to change source.6 For further information in applying calibrations, see Appendix C of the AIPS Cookbook (NRAO staff, 2006) or the relevant AIPS HELP files.