anchor.diff:  +
   The default is `<em>`.
   
  -`hl.tag.post`:: </em> |
  +`hl.tag.post`::
   (`hl.simple.post` for the Original Highlighter) Specifies the “tag” to use after a highlighted term. This can be any string, but is most often an HTML or XML tag.
   +
   The default is `</em>`.
  
positive.code: 
  The Unified Highlighter supports these following additional parameters to the ones listed earlier:
  
  `hl.offsetSource`:: _(blank)_ |
  By default, the Unified Highlighter will usually pick the right offset source (see above). However it may be ambiguous such as during a migration from one offset source to another that hasn't completed.
  +
  The offset source can be explicitly configured to one of: `ANALYSIS`, `POSTINGS`, `POSTINGS_WITH_TERM_VECTORS`, or `TERM_VECTORS`.
  
negative.code: `hl.formatter`::
  Selects a formatter for the highlighted output. Currently the only legal value is `simple`, which surrounds a highlighted term with a customizable pre- and post-text snippet.
  
  `hl.simple.pre`, `hl.simple.post`::
  Specifies the text that should appear before (`hl.simple.pre`) and after (`hl.simple.post`) a highlighted term, when using the `simple` formatter. The default is `<em>` and `</em>`.
  
  `hl.fragmenter`::
  Specifies a text snippet generator for highlighted text. The standard (default) fragmenter is `gap`, which creates fixed-sized fragments with gaps for multi-valued fields.
  +
  Another option is `regex`, which tries to create fragments that resemble a specified regular expression.
  
  `hl.regex.slop`::
  When using the regex fragmenter (`hl.fragmenter=regex`), this parameter defines the factor by which the fragmenter can stray from the ideal fragment size (given by `hl.fragsize`) to accommodate a regular expression.
  +
  For instance, a slop of `0.2` with `hl.fragsize=100` should yield fragments between 80 and 120 characters in length. It is usually good to provide a slightly smaller `hl.fragsize` value when using the regex fragmenter.
  