In some ways, choosing the right lockset for a commercial job is easy, since commercial building codes specify exactly which functions a lockset should have for a given situation. The commercial specifier then uses published resources that match code requirements to a manufacturer's product (see "Sources of Supply" at end of article). Because commercial-duty locksets reference ANSI and UL standards, the buyer can be reasonably assured of a product's quality. However, residential standards are less exact. Few buyers pay attention to ANSI standards or UL ratings. As a result, it's not immediately apparent what makes the difference between a good-quality residential lockset and a poor one. This article describes the terms you should know to help make sense of the manufacturers' literature, and