Why not simply look at the first two letters and see if they changed?

my $last = "";
while (<DATA>) {
    my (undef,$number,$item,$rest) = split /\s+/, $_, 4;
    my $current_two_letters = substr($item,0,2);
    if ($current_two_letters ne $last) {
        print "--- Break here (change from $last to $current_two_lette
+rs)\n";
    };
    print $_;
    $last = $current_two_letters;
};

__DATA__
   1930:    Nails               <-- #Na here
   1931:    Naked
   1941:    Nearsighted         <-- #Ne here
   1942:    Neck
   1961:    Newspaper_Reporter
   1963:    Nickname            <-- #Ni here
   1964:    Niece
   1971:    Nipples  
   1972:    Nobility            <-- #No here
   1973:    Noise  
   1981:    November
   1982:    Nuclear_Bomb        <-- #Nu here
   1984:    Numbers
   1989:    Nuts 
   1990:    Nymph

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In reply to Re: Programatically detecting a change in letters by Corion
in thread Programatically detecting a change in letters by hacker

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