diff --git a/documentation/ref-manual/variables.rst b/documentation/ref-manual/variables.rst
index e81a12030a..aaba23dbdf 100644
--- a/documentation/ref-manual/variables.rst
+++ b/documentation/ref-manual/variables.rst
@@ -5085,6 +5085,14 @@ system and gives an overview of their function and contents.
       result of the package manager in use, see the
       ":ref:`package.bbclass <ref-classes-package>`" section.
 
+   :term:`PACKAGE_DEBUG_FILE_SUFFIX`
+      This suffix is added to the names of all files with debug symbols that go
+      into the ``-dbg`` package. It can be used to make the debug files produced
+      by one recipe unique to avoid them conflicting with identically named
+      debug files produced by another recipe. This may be needed since while the
+      target files may be split in multiple packages, the debug files for one
+      recipe are all in one package.
+
    :term:`PACKAGE_DEBUG_SPLIT_STYLE`
       Determines how to split up and package debug and source information
       when creating debugging packages to be used with the GNU Project