Library /sys$common/syshlp/basichelp.hlb Constants, Integer  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  An integer constant is a literal or named  constant  with  one  or  more
  digits,  either  positive  or negative, with no fractional digits and an
  optional trailing percent sign (%).  The percent sign  is  required  for
  integer literals if the default data type is not INTEGER.