This guide describes several methods for identifying, counting, and learning something about homeless people who are unlikely to be found in shelters or in other residential programs within a local homeless assistance network. Collecting good baseline data about this subpopulation is essential to understanding the causes of homelessness and to designing effective responses, and can be used as a basis for comparison in future years. Information about these approaches was gathered from communities throughout the country and examples of their methods are provided throughout the guide. (Authors)