Since he's just 'passing through' the values, and CGI.pm parameters are 'sticky', this:

print hidden('hey','you');
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can be shortened to this:

print hidden('hey');
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In fact, you have to specifically pass an override flag if you want to override the 'sticky' default, so the first example wouldn't even work if you were trying to change the value of the 'hey' parameter.

Update:damian1301 is wrong below. See this:

$ perl -e 'use CGI qw(:standard -debug);print hidden("hey")' hey=you
<input type="hidden" name="hey" value="you">
$ perl -e 'use CGI qw(:standard -debug);
print hidden("hey","there")' hey=you
<input type="hidden" name="hey" value="you">
$ perl -e 'use CGI qw(:standard -debug);print hidden(-override=>1,
-name=>"hey",-value=>"there")' hey=you
<input type="hidden" name="" value="there">
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