{
  "resourceType": "SearchParameter",
  "id": "filter",
  "extension": [
    {
      "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-wg",
      "valueCode": "fhir"
    }
  ],
  "url": "http://hl7.org/fhir/SearchParameter/filter",
  "version": "1",
  "name": "FilterSearchParameter",
  "title": "Filter Search Parameter",
  "status": "draft",
  "experimental": false,
  "date": "2018-07-26",
  "publisher": "HL7 International / FHIR Infrastructure",
  "contact": [
    {
      "telecom": [
        {
          "system": "url",
          "value": "http://www.hl7.org/Special/committees/fiwg"
        }
      ]
    }
  ],
  "description": "This is the formal declaration for the _filter parameter, documented at [http://hl7.org/fhir/search_filter.html](http://hl7.org/fhir/search_filter.html)",
  "purpose": "Support combination searches when the simple name\u003dvalue basis of search cannot express what is required",
  "code": "_filter",
  "base": [
    "Resource"
  ],
  "type": "special"
}