# File lib/asciidoctor/parser.rb, line 1150
  def self.catalog_callouts(text, document)
    found = false
    text.scan(CalloutScanRx) {
      # lead with assignments for Ruby 1.8.7 compat
      captured, num = $&, $2
      document.callouts.register num unless captured.start_with? '\\'
      # we have to mark as found even if it's escaped so it can be unescaped
      found = true
    } if text.include? '<'
    found
  end