Private Variables

Let me elaborate a little. When we first started with Cache beta, all object references were in the symbol table (if I remember well, something like %obj). If you issued a naked Kill, all objects were gone.
Somehow, ISC managed to move them outside the regular symbol table. For these private (or hidden) variables, I suspect something similar could be achieved.

A good idea, but to avoid confusion (we already have 'private' variables - for example all the variables of a methd) instead of 'private variables' I would call them 'hidden variables' which in effect they should be.

Local variables can be used for this purpose.