[Djeman]

Code can not be documentation by meer definition. Code is written in programming language and documentation in spoken language. So documentation has important function of explaining intention of code in non trivial sections. Of course you wont give explanation of CRUD actions or other patterns you are using but business rules get coded and people reading that code need to know where rules come from and what are expectations either directly in code or by reference. Otherwise you revert to finding origin of code in source control and related task if you are lucky to have that level of tracking.