DelphiScript has the following specifics:

In TestComplete script units can refer to each other, so you can call routines and variables defined in one unit from another unit. DelphiScript supports circular references between units.
In Object Pascal, the body of a function or a procedure can contain declarations of other functions and procedures, for example:

Delphi

Delphi

procedure FuncA;

  procedure FuncB;
  begin
    …
  end;

begin
  …
end;

Nested routine declarations are not allowed in DelphiScript scripts that are run from TestComplete.
DelphiScript’s ExceptionMessage function cannot be evaluated in the TestComplete Watch List panel and Evaluate dialog.
If you have recursive code in the try block, after TestComplete exits the recursive loop, it will run the code in the except block regardless of whether any errors have occurred in the try block or not.

DelphiScript - Specifics of Usage