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

  A user-defined OpenVMS symbol or logical name.

  Digital Test Manager stores variables in its library
  for use when it executes tests. There are two types of
  variables:

  Global    Once created, global variables are accessible
            by any test in all collections if the
            test's template, prologue, or epilogue file
            references the variable.
  Local     Local variables are accessible only to a
            single test if the variable is referenced in
            the test's template, prologue, or epilogue
            file.