* `json_callback=<string>`
-Wrap json output in a callback function (JSONP) i.e. `<string>(<json>)`.
+Wrap json output in a callback function ([JSONP](https://en.wikipedia.org/wiki/JSONP)) i.e. `<string>(<json>)`.
Only has an effect for JSON output formats.
### Output details
* `zoom=[0-18]`
-Level of detail required for the address. This is a number that corresponds
+Level of detail required for the address. Default: 18. This is a number that corresponds
roughly to the zoom level used in map frameworks like Leaflet.js, Openlayers etc.
In terms of address details the zoom levels are as follows: