The DollarUnderscore and related variables are all evil.  The following is a use of two of them in PerlLanguage at once:

    while(<>) {
        if /begin\w+(.*?)\w+end/ {
             print $1, "\n";
        }
    }
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CategoryRant''''''*

*please add more ranting.  I can't be the ONLY one who thinks this...

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CategoryPerl