The "use utf8" pragma tells the Perl parser to allow UTF-8 in the pro-
gram text in the current lexical scope (allow UTF-EBCDIC on EBCDIC
based platforms). ...

Do not use this pragma for anything else than telling Perl that your
script is written in UTF-8. The utility functions described below are
useful for their own purposes, but they are not really part of the
"pragmatic" effect.