Yeah, I just missed the multiple records in the same file. Mea culpa

Then you can do something like:

%length = (HDR => 5, FTR => 10);
while(<DATA>)
{
   while(/(HDR|FTR)/) # find either HDR or FTR
   {
      substr($_, $-[1], $length{$1}) = ''; # $-[1] is the position of 
+the first capture groups (parenthesis)
   }
   print;
}
__DATA__
HDR--Hello this is a test FTR-------Should there be text here? HDR--Tw
+o records on the same line FTR-------
HDR--and here an incomplete footer FTR--
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