The block ID of this list item, if defined.
A single character indicating the checked status of a task.
The space character
' ' is interpreted as an incomplete task.
An other character is interpreted as completed task.
undefined if this item isn't a task.
Line number of the parent list item (position.start.line). If this item has no parent (e.g. it's a root level list), then this value is the negative of the line number of the first list item (start of the list).
Can be used to deduce which list items belongs to the same group (item1.parent === item2.parent). Can be used to reconstruct hierarchy information (parentItem.position.start.line === childItem.parent).