anchor.diff:  :rmhl <highlighter_id>
   ----------------------
   
  +`highlighter_id` is a name generated by the highlighter specified with `highlighter_name`,
  +possibly dependent on the parameters. Use command completion on rmhl to see the existing
  +highlighters id.
  +
   general highlighters are:
   
    * `regex <ex> <capture_id>:<face>...`: highlight a regex, takes the regex as
  
positive.code:             in place of line breaks
  
   * `>`: indent selected lines
   * `<`: deindent selected lines
   * `alt->`: indent selected lines, including empty lines
   * `<`: deindent selected lines
   * `alt-<`: deindent selected lines, do not remove incomplete
  
negative.code:  * `a`, `<` or `>`: select the enclosing <> block
   * `"`: select the enclosing double quoted string
   * `'`: select the enclosing single quoted string
   * ` ` `: select the enclosing grave quoted string
   * `w`: select the whole word
   * `W`: select the whole WORD
   * `s`: select the sentence
  