Commenting and Documentation in Free Code?

ckotchey asks: "Being new to the Linux/GPL world over the last few months, I'm amazed at the lack of informative comments that I'd like to find at the begining of each source file, and within the code itself. At a minumum, I'd like to see summary lists of functions, parameters, return values (and their meanings), etc., that are within the file I'm trying to dissect, along with some descriptive comments within the code to help understand what is happening. Without such comments, it seems counter-productive to the whole open-source concept of allowing others to see the code, understand the code, and fix/enhance the code (at least, in a timely manner!). Should there be, at a minimum, some sort of 'commenting standard' to be (at least voluntarily) followed by developers in the Linux/Open Source community?"