The following predefined variables are commonly used in AutoLISP applications:
NoteYou can change the value of these variables
with the setq function. However,
other applications might rely on their values being consistent; therefore,
it is recommended that you do not modify these variables. Visual
LISP, by default, protects these variables from redefinition. You
can override this protection through the VLISP Symbol Service feature
or by setting a VLISP environment option.