diff --git a/config/file_contexts.subs_dist b/config/file_contexts.subs_dist
index 32b87a4fd..a31a721fa 100644
--- a/config/file_contexts.subs_dist
+++ b/config/file_contexts.subs_dist
@@ -1,3 +1,13 @@
+# This file can is used to configure base path aliases as in:
+#
+# /aliased_path /original_path_as_configured_in_file_contexts
+#
+# where original_path_as_configured_in_file_contexts is a base
+# path being used in the main file_contexts configuration file.
+#
+# It does not perform substitutions as done by sed(1), for
+# example, but aliasing.
+# 
 /lib32 /lib
 /lib64 /lib
 /run /var/run