diff --git a/tsk/fs/ntfs.c b/tsk/fs/ntfs.c
index 7fa6b57d8b633af2757570047b171808c6c2546c..4d65ca691f7229c28fd6a588e659b7550c6cefad 100755
--- a/tsk/fs/ntfs.c
+++ b/tsk/fs/ntfs.c
@@ -2625,6 +2625,12 @@ ntfs_proc_attrlist(NTFS_INFO * ntfs,
         }
 
         if (processed_inum_list == NULL) {
+            /*
+             * Create a stack to keep track of inums already seen.
+             * The local mftSeenList variable is used to keep track
+             * of which iteration created the stack so that it can
+             * be correctly freed later.
+             */
             processed_inum_list = mftSeenList = tsk_stack_create();
         }