Q:\>perl -Mdiagnostics tmp.pl
Global symbol "%myHash" requires explicit package name at tmp.pl line 
+4.
Global symbol "$myHash" requires explicit package name at tmp.pl line 
+17.
Global symbol "%myHash" requires explicit package name at tmp.pl line 
+22.
Execution of tmp.pl aborted due to compilation errors (#1)
    (F) You've said "use strict vars", which indicates that all variab
+les
    must either be lexically scoped (using "my"), declared beforehand 
+using
    "our", or explicitly qualified to say which package the global var
+iable
    is in (using "::").
...
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I can't put it any better than diagnostics puts it.