diff --git a/docs/resources/retention_policy.md b/docs/resources/retention_policy.md
index 66bb2c7..880f442 100644
--- a/docs/resources/retention_policy.md
+++ b/docs/resources/retention_policy.md
@@ -52,6 +52,8 @@ resource "harbor_retention_policy" "main" {
 
 ### Nested Schema for `rule`
 
+~> Multiple tags or repositories must be provided as a comma-separated list wrapped into curly brackets `{ }`. Otherwise, the value is interpreted as a single value.
+
 Optional:
 
 - `always_retain` (Boolean) retain always.
diff --git a/templates/resources/retention_policy.md.tmpl b/templates/resources/retention_policy.md.tmpl
index eaa3d24..41e458e 100644
--- a/templates/resources/retention_policy.md.tmpl
+++ b/templates/resources/retention_policy.md.tmpl
@@ -37,6 +37,8 @@ For example, the {{ .SchemaMarkdown }} template can be used to replace manual sc
 
 ### Nested Schema for `rule`
 
+~> Multiple tags or repositories must be provided as a comma-separated list wrapped into curly brackets `{ }`. Otherwise, the value is interpreted as a single value.
+
 Optional:
 
 - `always_retain` (Boolean) retain always.