diff --git a/documentation/content/en/books/porters-handbook/makefiles/_index.adoc b/documentation/content/en/books/porters-handbook/makefiles/_index.adoc
--- a/documentation/content/en/books/porters-handbook/makefiles/_index.adoc
+++ b/documentation/content/en/books/porters-handbook/makefiles/_index.adoc
@@ -1466,7 +1466,10 @@
 |(none)
 
 |`GH_TUPLE`
-|`GH_TUPLE` allows putting `GH_ACCOUNT`, `GH_PROJECT`, `GH_TAGNAME`, and `GH_SUBDIR` into a single variable. The format is _account_`:`_project_`:`_tagname_`:`_group_`/`_subdir_. The `/`_subdir_ part is optional. It is helpful when there is more than one GitHub project from which to fetch.
+|`GH_TUPLE` allows putting `GH_ACCOUNT`, `GH_PROJECT`, `GH_TAGNAME`, and `GH_SUBDIR` into a single variable. The format is `_account:project:tagname:group/subdir_`. The `_group_` and `_/subdir_` parts are optional. They are helpful when there is more than one GitHub project from which to fetch.
+
+Note that `_group_` and `_/subdir_` are not separated by a `:` like the other parameters.
+|(none)
 |===
 
 [IMPORTANT]