anchor.diff:  [float]
   === Boolean Values
   
  -All REST APIs parameters (both request parameters and JSON body) support
  +All REST API parameters (both request parameters and JSON body) support
   providing boolean "false" as the value `false` and boolean "true" as the
   value `true`. All other values will raise an error.
   
  
positive.code: 
  Many users use a proxy with URL-based access control to secure access to
  Elasticsearch indices. For <<search-multi-search,multi-search>>,
  <<docs-multi-get,multi-get>> and <<docs-bulk,bulk>> requests, the user has
  the choice of specifying an index in the URL and on each individual request
  within the request body. This can make URL-based access control challenging.
  
  
negative.code: date string ending with `||`. This anchor date can optionally be followed by
  one or more maths expressions:
  
  * `+1h`: Add one hour
  * `-1d`: Subtract one day
  * `/d`: Round down to the nearest day
  
  The supported time units differ from those supported by <<time-units, time units>> for durations.
  The supported units are:
  
  [horizontal]
  `y`:: Years
  `M`:: Months
  `w`:: Weeks
  `d`:: Days
  `h`:: Hours
  `H`:: Hours
  `m`:: Minutes
  `s`:: Seconds
  
  Assuming `now` is `2001-01-01 12:00:00`, some examples are:
  
  [horizontal]
  `now+1h`:: `now` in milliseconds plus one hour. Resolves to: `2001-01-01 13:00:00`
  `now-1h`:: `now` in milliseconds minus one hour. Resolves to: `2001-01-01 11:00:00`
  `now-1h/d`:: `now` in milliseconds minus one hour, rounded down to UTC 00:00. Resolves to: `2001-01-01 00:00:00`
   `2001.02.01\|\|+1M/d`:: `2001-02-01` in milliseconds plus one month. Resolves to: `2001-03-01 00:00:00`
  
  [float]
  