code: def clean_content(content):
      
      for pattern, subst in _CLEAN_PATTERNS:
          content = pattern.sub(subst, content)
      return content
docs: \
      Removes paragraph numbers, section delimiters, xxxx etc. from the content.
      
      This function can be used to clean-up the cable's content before it
      is processed by NLP tools or to create a search engine index.
      
      `content`
          The content of the cable.