I have very similar code over multiple files in my project. If a client wanted some level of commented code, would I have to invest the time into duplicating the code for every file. I think it would simply be a waste of time. What would be the best/easiest way to provide comments to a client. (Refer them to a readme to show one file with the comments?) It's along the lines of URL's to point to and BOOL's to change. For Clarification: I don't want to, nor do I think it would be a good idea to consolidate code to create a single place for settings. If I was building a desktop app or using PHP, I would create a config file. But this isn't a situation where that would be called for. Infact, it might actually be considered (from what I understand) a best-practice. I totally get that It's a good idea to eliminate duplicate code, but I don't even think there's an efficient and simple way to eliminate the duplicate base code. My question pertains how I should Comment for clients/dev's in these sort of situations*Disclaimer: Next time, I'll start with comments rather than adding them in later. 
Do I Need To duplicate comments in Every File?
comments;client relations
If I understand you correctly, you are working with a framework that recommends a lot of very similar files, not repeating the logic, just structure - interface code that fits your classes into the framework.In this case, take one, most-representative file and comment it richly. Then in each similar file, give a shortie synopsis:  /* generic Controller for screen X. See @filename for general structure */If the file has significant differences, mention them in the header, then comment them near the exceptional piece.  /* special Controller for screen X. See @filename for general structure */  /* exceptional behavior: function Y adds an event listener Z, in order to   * handle the special behavior in case widget W receives new data. */