Douglas McIlroy, the original author of the Unix 'spell' command, provided further clarification and technical details on his work following a recent article discussing 'spell's data structure. In his email, he addressed the representation of data and criticized a particular formula that appeared unnecessarily complex. He elaborated on his methods for optimizing memory usage, including how he managed to compress dictionaries for faster transfer and processing. He detailed a system of storing affixing information, which allowed 'spell' to be more effective in grammar and spelling corrections. McIlroy cited improved performance metrics compared to previous iterations of 'spell' while discussing the importance of the computer environment on performance efficiency. He also hinted at the deep history and continuous evolution of Unix software, including the foundational changes made over time.