In this article we present the largest set of unitals (totally 553) in
projective planes of order 16. An open question is what is the number of the
known unitals that are non-isomorphic to the reported ones. The results are
obtained with a program that implements author's algorithm.Comment: 56 pages, included are the new found unitals in planes of Gordon
  Royle's and E. Moorhouse's formats planes representatio