A more canonical (and efficient) way of preserving order, whether the input data is sorted or not, would be along the lines of:

my %seen;
while ( <DATA> ) {
  s/\s+$//;  # Remove trailing spaces and newline.
  print "$_\n" unless $seen{$_}++;
}

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By the way, why do you use our instead of my?

In reply to Re^2: removing duplicate lines by Not_a_Number
in thread removing duplicate lines by Anonymous Monk

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