diff --git a/_api-reference/common-parameters.md b/_api-reference/common-parameters.md index 5b536ad9925..70a103ba1a1 100644 --- a/_api-reference/common-parameters.md +++ b/_api-reference/common-parameters.md @@ -123,4 +123,17 @@ Kilometers | `km` or `kilometers` Meters | `m` or `meters` Centimeters | `cm` or `centimeters` Millimeters | `mm` or `millimeters` -Nautical miles | `NM`, `nmi`, or `nauticalmiles` \ No newline at end of file +Nautical miles | `NM`, `nmi`, or `nauticalmiles` + +## `X-Opaque-Id` Header + +You can specify an opaque identifier on any request using the `X-Opaque-Id` header. This identifier is used to track tasks and deduplicate deprecation warnings in server side logs. This identifier is intended to differentiate different callers into your OpenSearch cluster. Do not specify a unique value per request. + +#### Example request + +The following request adds an opaque ID to the request: + +```json + +curl -H "X-Opaque-Id: my-curl-client-1" -XGET localhost:9200/_tasks +``` \ No newline at end of file