diff --git a/contribute/backend/errors.md b/contribute/backend/errors.md
index 674e3d84305..840e0c09829 100644
--- a/contribute/backend/errors.md
+++ b/contribute/backend/errors.md
@@ -105,6 +105,18 @@ unfortunately not readily available on pkg.go.dev because Grafana is not
 fully Go modules compatible, but can be viewed using
 [godoc](https://go.dev/cmd/godoc/) from the Grafana directory.
 
+### Error source
+
+You can optionally specify an error source that describes from where an
+error originates. By default it's _server_ and means the error originates
+from within the application, e.g. Grafana. The `errutil.WithDownstream()`
+option may be appended to the NewBase function call to denote an error
+originates from a _downstream_ server/service. The error source information
+is used in the API layer to distinguish between Grafana errors and
+non-Grafana errors to include this information when instrumenting the
+application and by that allowing Grafana operators to define SLO's
+based on actual Grafana errors.
+
 ### Handling errors in the API
 
 API handlers use the `github.com/grafana/grafana/pkg/api/response.Err`