From Lavish Software Wiki
Defining an Item
An Item is defined by a JSON object, usually in the "items" Array of an Item List.
|itemType||The type of Item, or "default" if not provided. This indicates what other properties the Item has. Items of the "default" type will be interpreted directly as a LGUI2 Element.|
|itemAs||For a "default" type of Item, this will specify whether an itemview is to be defined as "content" or "children" within the itemview.|