diff --git a/specification/metrics/semantic_conventions/system-metrics.md b/specification/metrics/semantic_conventions/system-metrics.md
index 11b97442e6d..16611347908 100644
--- a/specification/metrics/semantic_conventions/system-metrics.md
+++ b/specification/metrics/semantic_conventions/system-metrics.md
@@ -7,6 +7,10 @@ metrics in OpenTelemetry. Consider the [general metric semantic
 conventions](README.md#general-metric-semantic-conventions) when creating
 instruments not explicitly defined in the specification.
 
+When reporting `system.*` metrics from inside a container, they SHOULD be
+reported for the container and not the host, unless the resource attributes
+specifically describe the host.
+
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