# Criteria for retrieving landmark information

The `criteria` object specifies what landmark information is returned and how the returned information is sorted.

Each `GetList` call targets one type of landmark information:

- Landmark

- Landmark category

- Landmark database

For more information about the types, see the Landmarks Service overview page.

The `criteria` object has three main properties: `Type`, `Filter`, and `Sort`. These are described in the following table. Properties enclosed in brackets are optional.

Table: Criteria object properties
Property | Description | Type | Value
--- | --- | --- | ---
`criteria.Type` | Specifies the type of landmark information to retrieve. Note: The available `Filter` properties depend on the selected type. | string | Possible values: `"Landmark"` `"Category"` `"Database"`
`[criteria.Filter]` | Specifies how the information to be retrieved is filtered. The properties of this object depend on the specified `Type`: Landmark properties Landmark category properties Landmark database properties If the `Filter` property is not specified, `GetList` returns a list of all the available landmarks, landmark categories, or landmark databases, depending on the specified `Type`. | object | For example: `criteria``.Filter.LandmarkName`
`[criteria.Sort]` | Specifies how the returned list of information is sorted. | object | Object with the properties specified below
`[criteria.Sort.Key]` | Specifies the information field (object property) to sort by. | string | Possible values: If `Type` is `"Landmark"`: `"LandmarkName"` If `Type` is `"Category"`: `"CategoryName"` If `Type` is `"Database"`: `"DatabaseURI"`
`criteria.Sort.Order` | Specifies the sort order. The default value for this property depends on `Type`: If `Type` is `"Landmark"`: `"Ascending"` If `Type` is `"Category"`: No default value If `Type` is `"Database"`: `"Ascending"` | string | Possible values: `"Ascending"` `"Descending"`