Yep, global vars are generally bad! The lisp variable field is one case where you can't get away from them :ugly:. Though you could use one of the user sysvars instead.
Another place is to store default user input between calls to your routine. Though here there are also alternatives, e.g. registry, file, blackboard, vlax-ldata, etc.
Rule of thumb is to always use localized vars, if you must go for global then try to distinguish them from other keywords. The official lisp naming convention is to prefix & suffix the name with asterisks.
