docs: def raw_html_filter(key: str, value: list, format: str, meta: Any) -> Optional[list]:
      """Filter the JSON ``value`` for raw html to convert to LaTeX.
  
      Arguments
      ---------
      key
          Key of the structure
      value
          Values in the structure
      format
          Output format of the processing
      meta
          Meta information
      """
      if key == "RawInline" and format == "latex" and value[0] == "html":
          if value[1] == "<sup>":
              filtered = [RawInline("latex", r"\textsuperscript{")]
          elif value[1] == "</sup>":
              filtered = [RawInline("latex", "}")]
          elif value[1] == "<sub>":
              filtered = [RawInline("latex", r"\textsubscript{")]
          elif value[1] == "</sub>":
              filtered = [RawInline("latex", "}")]
          else:
              return None
          return filtered
  
      return None