Actually, their name exists of a single control character, although they are to be written in the source as a caret+letter. For example, for $^W, the name is ctrl-W. If anybody find this hard to believe, try looking into the stash %:: ,the keys are the names for the global variables in main::.

use Data::Dumper;
$Data::Dumper::Useqq = 1;
print Dumper \%::;
[download]

Me, I have a hard time calling a control character, a "punctuation character".