function asciiOnlyToLowerCase (input) {
    var result = ''
    for (var i = 0; i < input.length; ++i) {
      if (input[i] >= 'A' && input[i] <= 'Z') {
        result += input[i].toLowerCase()
      } else {
        result += input[i]
      }
    }
    return result
  }
Generates an anchor for the given header and mode.

@name anchorMarkdownHeader
@function
@param header      {String} The header to be anchored.
@param repetition  {Number} The nth occurrence of this header text, starting with 0. Not required for the 0th instance.
@return            {String} The header anchor id