OSM tag name=Foster Island matches Foster Island in these Wikidata fields:
| Islands of King County, Washington | place=islet, place=island, boundary=administrative, admin_level |
| Islands of Seattle | place=islet, place=island, boundary=administrative, admin_level |
| Lake islands of Washington (state) | place=islet, place=island, boundary=administrative, admin_level |
| Uninhabited islands of Washington (state) | place=islet, place=island, boundary=administrative, admin_level |