  This white paper specifies the footprints, cadence requirements, and
total-depth requirements needed to allow the most-successful AGN studies in the
four currently selected LSST Deep-Drilling Fields (DDFs): ELAIS-S1, XMM-LSS,
CDF-S, and COSMOS. The information provided on cadence and total-depth
requirements will also likely be applicable to enabling effective AGN science
in any additional DDFs that are chosen.
