This does seem rather voodoo-ish at first, until we read the documentation.
"
perldoc perlvar" reveals that $^H holds, "the current set of syntax checks enabled by use
strict and other block scoped compiler hints". It would seem to me
that all of the actual strict code is built into the perl binary,
and strict.pm uses tricks like bitmasks to set certain bits in this
variable, telling perl to turn on/off certain parts of the strict checking code. You could set the bits
yourself, if you wanted to live semi-dangerously.
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IndyZ