diff --git a/src/mame/drivers/oneshot.c b/src/mame/drivers/oneshot.c
index c0c997977ab..e53ac0a5b5a 100644
--- a/src/mame/drivers/oneshot.c
+++ b/src/mame/drivers/oneshot.c
@@ -446,6 +446,15 @@ ROM_START( maddonna )
 	ROM_LOAD( "x1", 0x00000, 0x10000, CRC(6b213183) SHA1(599c59d155d11edb151bfaed1d24ef964462a447) ) // motherboard rom, zooming?
 ROM_END
 
+// The tiles containing the copyright string (tiles 0x3979 onwards) differ in this set.
+// Both versions have tiles containing the 'Tuning - Germany' copyright messages, but
+// the parent set has additional tiles containing the '(c)Copyright 1995' which is shown
+// on the title screen.
+//
+// The lack of these tiles in this set causes all subsequent tiles to be shifted.  It is
+// likely that the correct program roms for this set either don't show '(c)Copyright 1995'
+// or display it using the regular font instead.
+
 ROM_START( maddonnb )
 	ROM_REGION( 0x40000, "maincpu", 0 ) /* 68000 Code */
 	/* program roms missing in this dump, gfx don't seem 100% correct for other ones */