We have an Excel report generating code at work. It's extremely straightforward to read... once you understand the requirements and limitations, and some intri

We have an Excel report generating code at work. It's extremely straightforward to read... once you understand the requirements and limitations, and some intricacies of Excel format. So there's a 5-page accompanying document that explains those. Code is very, very rarely self-documenting on its own. Because more often than not you need to know most of the code, most of the context and history of the code, and the business domain this code is intended for to understand it.