is it allowed to use the identifier "specialize" as constant (or type or var)?

Because it compiles with 3.3.1. (the line that defines the constant).

But it seems it can't be used.
At least it fails in the below scenario, when trying to use as value.

program foo;
{$mode objfpc}{$H+}
const specialize = 1; // compiles
var a: integer;
begin
   if a = specialize then // error // comment out for fail on next line
     a:=specialize; // error
end;