Remember when you were a kid and your teacher sent home a note to your parents? You knew you were in big-time trouble, so why not just hide the note? What your parents don't see can't hurt you, right? Well, this is kind of like that. If an investment rep receives a written complaint from a client, they are obligated to pass it along to their employer, who is in turn obligated to add it to the rep's U-4. Knowing that, it's probably tempting to just not pass it along, but it's a major violation if caught.