diff --git a/contributing_to_docs/doc_guidelines.adoc b/contributing_to_docs/doc_guidelines.adoc
index bcafbe93fea7..602c66af6a22 100644
--- a/contributing_to_docs/doc_guidelines.adoc
+++ b/contributing_to_docs/doc_guidelines.adoc
@@ -736,6 +736,10 @@ a|*cluster-admin* user
 *RubyGems*
 
 |Filenames or directory paths
+
+If you need to include a variable in the filename or directory path, follow
+the guidance for system or software variables for the variable.
+
 a|$$*_filename_*$$
 
 $$*_directory_*$$