sort {...} chomp <DATA>;

##</code><code>##

print       
    map {
        substr( $_, 16 )    
    }
    sort    
    map {
        /^(\d+)       # digits of type
          (\D+)       # type character
          (\d+)       # part
          (\D*)       # detail (optional)
          R(\d+)      # revision count
          B?(\d*)     # alternate count (optional)
          \.(vec|ras) # file extension
          \s+$        # trailing whitespace
        /x
            ? sprintf( '%3s%03d%03d%2s%03d%1d%1s', # numbers add up to 16
                $7, 999 - ($6 || 0), $1, $2, $3, $5, $4, ) . $_
            : ('x' x 16) . $_
    }
    <DATA>;
##</code><code>##

sub part_sort {
    ...
}
sort part_sort <DATA>;

##</code><code>##

print sort part_sort <DATA>;