diff --git a/etc/conf/app.conf b/etc/conf/app.conf
index 38b6690..0e1e9ba 100644
--- a/etc/conf/app.conf
+++ b/etc/conf/app.conf
@@ -92,6 +92,13 @@
 cipher_plugin = ""
 
 # suppot buildin, unlimit
+# in buildin mode(default): microservice capacity is 50000
+#                           instance capacity is 150000
+#                           schema capacity of single microservice is 100
+#                           rule capacity of single microservice is 100
+#                           tag capacity of single microservice is 100
+# in unlimit mode: all resource capacities are unlimited, including
+#                  microservices, instances, schemas, rules, tags
 quota_plugin = ""
 
 #access control plugin