  In this paper we describe a new UV-initiative HST project (GO-13297) that
will complement the existing F606W and F814W database of the ACS Globular
Cluster (GC) Treasury by imaging most of its clusters through UV/blue WFC3/UVIS
filters F275W, F336W and F438W. This "magic trio" of filters has shown an
uncanny ability to disentangle and characterize multiple-population (MP)
patterns in GCs in a way that is exquisitely sensitive to C, N, and O abundance
variations. Combination of these passbands with those in the optical also gives
the best leverage for measuring helium enrichment. The dozen clusters that had
previously been observed in these bands exhibit a bewildering variety of MP
patterns, and the new survey will map the full variance of the phenomenon. The
ubiquity of multiple stellar generations in GCs has made the formation of these
cornerstone objects more intriguing than ever; GC formation and the origin of
their MPs have now become one and the same problem. In the present paper we
will describe the data base and our data reduction strategy, as well as the
uses we intend to make of the final photometry, astrometry, and proper motions.
We will also present preliminary color-magnitude diagrams from the data so far
collected. These diagrams also draw on data from GO-12605 and GO-12311, which
served as a pilot project for the present GO-13297.
