When using the BRDF to learn about surface statistics or for use in a stray radiation code the assumption is usually made that the surface is isotropic. Unfortunately, this is often not the case and sometimes means that the BRDF cannot be used to characterize the sample. Non-isotropic surfaces, such as machined or rolled surfaces cause some issues. Scatter caused by small discrete surface features such as scratches, pits or particles cannot be characterized by BRDF at all. Scatter from an extended edge also results in analysis issues. In these situations the measurements may be made differently and the measured BRDF needs to be adjusted to get a scatter quantifier that can be related to sample characteristics. The situation is further complicated by the fact that the popular stray radiation codes used to analyze many optical systems accept scatter data only in the standardized BRDF format. This talk reviews these situations for both measurement and analysis issues.