Management and developers have given insufficient attention to software maintenance, the most expensive phase of the software life cycle. Standards have improved the ability to develop and design software, but most standards do not deal with the maintenance phase in a substantive way. SECNAVINST 3560.1, Tactical Digital Systems Documentation Standard for Software Maintenance, was evaluated with respect to its usability for software maintenance. Recommendations are made for improving the maintainability aspects of this instruction. (Author)