occurrence

   An occurrence is any instance of an entity in your program. An
   entity can be any language construct, such as a variable, a
   routine, or a constant. To further clarify this, consider the
   following code fragment (not written in a particular language):

     1   MODULE myprog;
     2
     3   VAR i,j;
     4
     5   ROUTINE foo()
     6   BEGIN
     7       i = 5;
     8       j = i;
     9   END;
     10  END;

   The code contains four entities: myprog, foo, i, j. There is one
   occurrence each of the module myprog, and the routine foo. The
   variable i, however, has three occurrences, and the variable j has
   two.