diff --git a/src/structs.h b/src/structs.h
index d6f9030..eb4f60e 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -742,6 +742,15 @@
 #endif
 } memline_T;
 
+// Values for the flags argument of ml_delete_flags().
+#define ML_DEL_MESSAGE	    1	// may give a "No lines in buffer" message
+#define ML_DEL_UNDO	    2	// called from undo, do not update textprops
+
+// Values for the flags argument of ml_append_int().
+#define ML_APPEND_NEW	    1	// starting to edit a new file
+#define ML_APPEND_MARK	    2	// mark the new line
+#define ML_APPEND_UNDO	    4	// called from undo
+
 
 /*
  * Structure defining text properties.  These stick with the text.