Defaults to INTERNAL if not set.

Setting idFormat to EXTERNAL changes the behaviour of the request and response. For the request the id parameter must be a string external id when referencing:

• object
• field
• type
• reservationMode

For the response the above list of items (if present) will be referenced by external id instead of internal.

Values that change from integer to string when changing idFormat are shown as either integer or string in the documentation. This is true both for the request and the response.