diff --git a/src/makeBaseExt/top/configure/CONFIG_SITE b/src/makeBaseExt/top/configure/CONFIG_SITE
index 8bc83a09c..71bc002e0 100644
--- a/src/makeBaseExt/top/configure/CONFIG_SITE
+++ b/src/makeBaseExt/top/configure/CONFIG_SITE
@@ -3,12 +3,12 @@
 # Make any extensions-specific changes to the EPICS build
 # configuration variables in this file.
 #
-# Host/target specific settings can be specified in files named
-#  CONFIG_SITE.$(EPICS_HOST_ARCH).Common
-#  CONFIG_SITE.Common.$(T_A)
-#  CONFIG_SITE.$(EPICS_HOST_ARCH).$(T_A)
+# Host/target specific settings are in os subdirectory files named
+#  os/CONFIG_SITE.$(EPICS_HOST_ARCH).Common
+#  os/CONFIG_SITE.Common.$(T_A)
+#  os/CONFIG_SITE.$(EPICS_HOST_ARCH).$(T_A)
 
-# Extensions should not normally be built for cross targets
+# Extensions are not normally built for cross targets
 CROSS_COMPILER_TARGET_ARCHS =
 
 # If you don't want to install into $(TOP) then