# Criteria for organizing landmarks in a landmark category

The `criteria` object specifies which landmarks to associate or disassociate and with which landmark category.

The `criteria` object has three main properties: `Type`, `Data`, and `OperationType`. These are described in the following table.

Table: Criteria object properties
Property | Description | Type | Value
--- | --- | --- | ---
`criteria.Type` | Specifies the type of landmark information to organize. This is always `"Landmark"`. | string | Possible values: `"Landmark"`
`criteria.Data` | Specifies which landmarks to organize, in which landmark category, and how (associate or disassociate). | object | Object with the properties specified below
`[criteria.Data.DatabaseURI]` | Specifies the URI of the landmark database in which the landmarks are organized. If this property is not specified, the landmarks are organized in the default database. | string | For example: `file://c:landmarks.ldb`
`criteria.Data.id` | Specifies the ID of the landmark category to organize. The specified landmarks are associated or disassociated with this category. Use the `GetList` method to retrieve this ID. | string |
`criteria.Data.IdList` | Specifies the IDs of the landmarks to organize. These landmarks are associated or disassociated with the specified category. Use the `GetList` method to retrieve these IDs. Note: If any of the specified landmarks does not exist, it is ignored and the operation is performed on the other landmarks. If any of the specified landmarks is already associated/disassociated with the specified category, it is ignored. | array of strings |
`criteria.OperationType` | Specifies whether to add the landmarks to the category (associate) or remove the landmarks from the category (disassociate). | string | Possible values: `"Associate"` `"Disassociate"`