diff --git a/content/en/tracing/guide/setting_primary_tags_to_scope.md b/content/en/tracing/guide/setting_primary_tags_to_scope.md
index 63046bdeb14..2cb3e34eb3a 100644
--- a/content/en/tracing/guide/setting_primary_tags_to_scope.md
+++ b/content/en/tracing/guide/setting_primary_tags_to_scope.md
@@ -80,6 +80,7 @@ Go to the [APM Settings][6] page to define, change, or remove your primary tags.
 * Changes may take up to two hours to be reflected in the UI.
 * The tracer always adds `resource`, `name`, and `service` tags to spans. Datadog recommends never adding these as host level tags to avoid confusion.
 * The additional primary tags support up to 100 unique values per tag. See [APM data volume guidelines][9] for details.
+* Additional primary tags can be host or container tags. Span-level tags added by the tracer cannot be used as primary tags.
 
 If you change a previously set primary tag, be aware of the following: