Almost any topic in CS has a multitude of edge cases and potential pitfalls. I've learned quite a few tricky edges to things I had never considered just reading

Almost any topic in CS has a multitude of edge cases and potential pitfalls. I've learned quite a few tricky edges to things I had never considered just reading through RFCs and standards docs on topics like calendars, Unicode, floating point numbers, and lots more. Practical guides like these blog posts of "Things I've really encountered problems with" are just the sprinkles on top. Such a wiki would be great, but it would basically amount to collecting all the practical knowledge of every domain to which computers have ever been applied!