$ret = $1 if $g =~ /\n\s*\n((?m:^#.*\n)+)$id/;

##</code><code>##

/\n\s*\n        # This matches your blank line between comments.
 (              # Capture into $1.
   (?m:         # Don't capture, but match this group as multiline. Which means match '^' and '$'
                # at the beginning or end of any line in the string.
      ^#        # Match the comment delimiter at the start of a line.
      .*\n      # Match everything up to, and including, the newline at the end of a line.
   )+           # Match this group one or more times.
 )              # End of $1 capture.
 $id            # This is the key you're looking for.
/x