The index is honored only when sorting, filtering and grouping are inactive; any of those view transforms overrides the insertion position and the item is appended to the end of the source collection. When paging is enabled, values in the range 0..PageSize - 1 map to positions within the current page, while values less than zero or greater than or equal to PageSize keep the original add-new behavior. When paging is disabled, non-negative values are treated as positions within the full source collection. The default value for this property is -1.