# File lib/asciidoctor/lexer.rb, line 882
  def self.catalog_callouts(text, document)
    text.scan(REGEXP[:callout_scan]) {
      # alias match for Ruby 1.8.7 compat
      m = $~
      next if m[0].start_with? '\\'
      document.callouts.register(m[1])
    }
  end