With the tags you provide, wouldn't something like the following be more discerning? 
Utilitarian@busybox ~$cat tmp/tmp.pl
#!/usr/bin/perl

use strict;
use warnings;
my $prefix='DOC_';
for (<DATA>){
    chomp(my $line=$_);
    print "$line\n" if ($line =~ /^$prefix[0-9]{3}(_|-)[0-9]{3}$/);
}

__DATA__
DOC_001_123
DOC_002_214
DOC_001-548
DOC_001-987
Utilitarian@busybox ~$perl tmp/tmp.pl
DOC_001_123
DOC_002_214
DOC_001-548

[download]
EDIT

bart below is correct, to constrain the matches to hyphens the regex above should have read /^$prefix[0-9]{3}-[0-9]{3}$/

print "Good ",qw(night morning afternoon evening)[(localtime)[2]/6]," fellow monks."

In reply to Re: Regex MATCH by Utilitarian
in thread Regex MATCH by stallion

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