#!/usr/local/bin/perl -w
use strict;

my $file = do{local $/; <DATA>};

$file =~ s/ < (?!=BR) [^>]* > //gsmx;
 
print $file;

exit;


__DATA__
<P ID="pStyle21X0"><SPAN ID="textStyle14">Parthenogenesis . . . . . . 
+. . . . . . . . 592 <BR>Patents on Life-Forms . . . . . . . . . . . 5
+94 <BR>Paternity Tests . . . . . . . . . . . . . . . 596 <BR>Pedigree
+ Analysis . . . . . . . . . . . . . 599 <BR>Penetrance . . . . . . . 
+. . . . . . . . . . 602 <BR>Phenylketonuria (PKU) . . . . . . . . . .
+ 604 <BR>Plasmids . . . . . . . . . . . . . . . . . . 606 <BR>Polygen
+ic Inheritance . . . . . . . . . . . 609 <BR>Polymerase Chain Reactio
+n . . . . . . . . 611 <BR>Polyploidy . . . . . . . . . . . . . . . . 
+. 613 <BR>Population Genetics . . . . . . . . . . . . 617 <BR>Prader-
+Willi and Angelman </SPAN>^M
</P>^M
<P ID="pStyle21X4"><SPAN ID="textStyle14">Syndromes. . . . . . . . . .
+ . . . . . . 623 <BR>Prenatal Diagnosis . . . . . . . . . . . . . 626
+ <BR>Prion Diseases: Kuru and </SPAN>^M
</P>^M
<P ID="pStyle21X4"><SPAN ID="textStyle14">Creutzfeldt-Jakob Syndrome .
+ . . . . . 631 <BR>Protein Structure . . . . . . . . . . . . . 634 <B
+R>Protein Synthesis. . . . . . . . . . . . . . 638 <BR>Proteomics . .
+ . . . . . . . . . . . . . . . 643 </SPAN>^M
^M
<SPAN ID="textStyle14">Pseudogenes . . . . . . . . . . . . . . . . 646
+ <BR>Pseudohermaphrodites . . . . . . . . . . 648 <BR>Punctuated Equi
+librium. . . . . . . . . . 650 </SPAN>^M
</P>^M
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I would expect that this would print out the data with only "BR" tags remaining.... however this is what I get:

Parthenogenesis . . . . . . . . . . . . . . 592 Patents on Life-Forms 
+. . . . . . . . . . . 594 Paternity Tests . . . . . . . . . . . . . .
+ . 596 Pedigree Analysis . . . . . . . . . . . . . 599 Penetrance . .
+ . . . . . . . . . . . . . . . 602 Phenylketonuria (PKU) . . . . . . 
+. . . . 604 Plasmids . . . . . . . . . . . . . . . . . . 606 Polygeni
+c Inheritance . . . . . . . . . . . 609 Polymerase Chain Reaction . .
+ . . . . . . 611 Polyploidy . . . . . . . . . . . . . . . . . 613 Pop
+ulation Genetics . . . . . . . . . . . . 617 Prader-Willi and Angelma
+n ^M
^M
Syndromes. . . . . . . . . . . . . . . . 623 Prenatal Diagnosis . . . 
+. . . . . . . . . . 626 Prion Diseases: Kuru and ^M
^M
Creutzfeldt-Jakob Syndrome . . . . . . 631 Protein Structure . . . . .
+ . . . . . . . . 634 Protein Synthesis. . . . . . . . . . . . . . 638
+ Proteomics . . . . . . . . . . . . . . . . . 643 ^M
^M
Pseudogenes . . . . . . . . . . . . . . . . 646 Pseudohermaphrodites .
+ . . . . . . . . . 648 Punctuated Equilibrium. . . . . . . . . . 650 
+^M
^M
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What am I missing? Should not the (?!=BR) cause the regex to not match the <BR> tags?