Thanks stevieb. I know changes are in perldelta, but I've seen several places in the docs where it mentions minimum version needed for a feature ...

perlrun:
As of 5.8.1, the -C can be followed either by a number or a list of op
+tion letters.

perlrun:
Note: Since perl 5.10.1, if the -C option is used on the #! line, it m
+ust be specified on the command line as well

perlretut:
The //a modifier, available starting in Perl 5.14, is used to restrict
+ the matches of \d, \s, and \w to just those in the ASCII range.
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