G'day Raymond,

Here's a few examples that may clarify the differences between handling UTF-8 in your output and in your source code. Here's how those characters should render: &#xc4; = Ä and &#x394; = Δ. I've used <pre>...</pre> tags so that the characters (e.g. Δ), and not the entities (e.g. &#x394;), are displayed.

Baseline code generating "Wide character" warning:

$ perl -Mstrict -Mwarnings -E '
    say "\xC4 and \x{0394} look different";
'
Wide character in say at -e line 2.
Ä and Δ look different

Using binmode function to specify UTF-8 output:

$ perl -Mstrict -Mwarnings -E '
    binmode STDOUT => ":utf8";             
    say "\xC4 and \x{0394} look different";
'
Ä and Δ look different

Using the open pragma to specify UTF-8 output:

$ perl -Mstrict -Mwarnings -E '
    use open qw{:std :utf8};
    say "\xC4 and \x{0394} look different";
'
Ä and Δ look different

Attempting to use UTF-8 in the source code without letting Perl know:

$ perl -Mstrict -Mwarnings -E '
    binmode STDOUT => ":utf8";
    say "\xC4 and \x{0394} look different";
    say "Ä and \x{c4} look different";
    say "Δ and \x{0394} look different";
'
Ä and Δ look different
Ä and Ä look different
Δ and Δ look different

Using the utf8 pragma to tell Perl there's UTF-8 in the source code:

$ perl -Mstrict -Mwarnings -E '
    use utf8;
    binmode STDOUT => ":utf8";
    say "\xC4 and \x{0394} look different";
    say "Ä and \x{c4} look the same";
    say "Δ and \x{0394} look the same";
'
Ä and Δ look different
Ä and Ä look the same
Δ and Δ look the same