d STB-41 dm53. Detection and deletion of duplicate observations. d STB insert by d Thomas J. Steichen, RJRT; d Nicholas J. Cox, University of Durham, UK. d Support: steicht@@rjrt.com and n.j.cox@@durham.ac.uk d After installation, see help ^dups^. f dm53/dups.ado f dm53/dups.hlp