diff --git a/xCAT-test/bats/README.md b/xCAT-test/bats/README.md
index f95850819..4e70ec6f2 100644
--- a/xCAT-test/bats/README.md
+++ b/xCAT-test/bats/README.md
@@ -75,6 +75,11 @@ require `cmp` from diffutils. The CI environment provides these dependencies.
 Missing prerequisites fail on Linux; non-Linux hosts report a skip.
 The temporary filesystem must allow executable files.
 
+The BMC cases check LAN values, device and channel selection, write retries,
+configuration defaults, user selection, and vendor port commands. They assert
+the commands issued by the complete script. They do not verify that physical
+BMC firmware accepts those commands.
+
 ## Boot artifact and repository checks
 
 `mknb_genesis_compression.bats`, `dhcp_http_port.bats` and