diff --git a/docs/observability/opentelemetry_v2.md b/docs/observability/opentelemetry_v2.md
index 5b5c33f30..a463d9159 100644
--- a/docs/observability/opentelemetry_v2.md
+++ b/docs/observability/opentelemetry_v2.md
@@ -236,6 +236,13 @@ litellm_settings:
 
 Each preset adds its own destination, so your spans reach all of them in parallel, each in that tool's native format.
 
+A preset exports only to its own backend. To also send plain `gen_ai.*` spans to your own OTLP collector, list `otel` next to the presets and set the `OTEL_*` env vars; a preset on its own ignores them, so vendor vocabulary such as `langfuse.*` or OpenInference never lands on your collector.
+
+```yaml title="config.yaml"
+litellm_settings:
+  callbacks: ["otel", "langfuse_otel"]
+```
+
 :::
 
 ### Preset reference