Software engineering is the study and an application of engineering to the design, development, and maintenance of software. Documentation engineering has become a very important aspect in the software engineering community. The role of documentation in a software engineering environment is to communicate information to its audience and instil knowledge of the system and efficiently allow for future software development. An engineered solution to the documentation problem would involve allocating appropriate resources to document adequate knowledge about the system to the extent that both current and future development will optimally benefit. Unfortunately, neither do we fully understand the impact of documentation on current or future development,nor what aspects of documentation contribute to its ability to communicate effectively. We do not really know to what extent we should document in order to balance the trade-offs between, on the one hand, allocating too many resources for documentation thus hindering present development; and, on the other hand, not allocating enough resources and thus hindering future development. This book focuses on the issue of documentation quality.