Library /sys$common/syshlp/dtm$dw_helplib.hlb mu, t_mu, t_memi  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  Choose the Mask... menu item to invoke the Digital
  Test Manager Screen Editor, which enables you to define
  areas on a DECwindows benchmark image that Digital Test
  Manager will not compare against the test results when
  the test is run in a collection.

  You can automatically read a DECwindows benchmark image
  (if it exists) into the Screen Editor by clicking on a
  DECwindows test in the view window, then pulling down
  the Testing menu and choosing the Mask... menu item.

  The Screen Editor operates on DDIF files only.