Changes is an enumerated list to specify whether something has added or removed, or wasn't changed at all.

Table: Changes

ParameterTypeRequired[a]DefaultDescription
Addedboolean  Whether the change is an addition.
NoChangeboolean  Whether there the result is no change.
Removedboolean  Whether the change is a removal.

[a] Some arguments may be required, as indicated in this column. For some fields, this column indicates that a result will always be returned for it.