George,

The PUBLIC and LOCAL statements declare variables and initialize them to .F.
The PRIVATE statement doesn't declare a variable at all but hides any variables with the same name if they exist up to the caling chain. The following code demonstrates that

PRIVATE lcVar
? lcVar     && Error: Variable not found
LOCAL lcVar
? lcVar     && No Error>

>
>By default any variables declared as PRIVATE or LOCAL are initialized to .F.
>
>What I do is to add the variables to a LOCAL statement as I first access or assign them.
>
>This is really a problem with testing. If you properly test the code, then these issues go away.