According to this doctrine, the functional features of a trademark, or those features having primarily a utilitarian purpose, are not granted trademark protection. Where the product requires the trademarked element in order to function optimally, then that element may not be protected by trademark law.Some courts have even barred trademark protection where product features such as shape, color or design increase the aesthetically pleasing nature of the product such that they improve the product's saleability. In recent years, however, the courts have moved away this rigid application of aesthetic functionality. Instead of barring features that serve as an "important ingredient" in the saleability of a product, courts have instead adopted a test inquiring whether the allegedly functional design is "necessary to effective competition." If so, then that element is deemed functional, and thus not protectable as a trademark.