/sys$common/syshlp/helplib.hlb FORTRAN, Intrinsic Procedures, LOC  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  LOC (arg)

  Returns the actual storage address of a data element.  The argument
  can be any data value.  The result is an INTEGER*4 data type.  In
  the case of global symbols, LOC returns the value of the symbol
  rather than its address.

  The LOC intrinsic serves the same purpose as the %LOC built-in
  function.