The Center for Devices and Radiological Health (Center) is concerned that there are a number of areas of confusion in the understanding of the requirements for Class IIIb and IV laser light shows and devices. In addition, several of the conditions used in most variances are not understood and are being ignored. This notice provides guidance to help manufacturers understand (1) what a variance is, (2) who is or is not covered by a specific variance, (3) when a variance must be amended, (4) what the various reporting and notification conditions mean, (5) the role of the laser product reporting guide, the laser light show reporting guide, and the notification letter, and (6) what certain misunderstood variance conditions actually mean.