2.1.23 [ECMA-262-1999] Section 10.2.1, Global Code
V0036:
The scope chain is created and initialised to contain the global object and no others.
Variable instantiation is performed using the global object as the variable object and using property attributes { __DontEnum,__ DontDelete }.
The this value is the global object.
JScript 5.x variable instantiations creates properties of the global object that have the DontEnum attribute.