Looking at the news.arc code, user profiles are stored as files in the directory arc/news/profile/, so the names there are case sensitive because of the underly

Looking at the news.arc code, user profiles are stored as files in the directory arc/news/profile/, so the names there are case sensitive because of the underlying file system. The users are loaded into a map using the name as a key, and map lookups are case sensitive in Arc. Thus, both the on-disk and in-memory storage of users is case sensitive. Of course names could be converted to a case-insensitive form, but the "natural" implementation results in case-sensitivity. The code can be downloaded from http://ycombinator.com/arc/arc3.tar http://ycombinator.com/arc/arc3.tar Note the code is from 2009 and didn't exactly match the running HN code at the time, so any conclusions from the published code aren't guaranteed. I did an analysis of the HN ranking formula back in 2009 - http://www.righto.com/2009/06/how-does-newsyc-ranking-work.html http://www.righto.com/2009/06/how-does-newsyc-ranking-work.h... - but the live formula is surely very different from the published code by now. And ironically, that article got about 0 upvotes so it didn't rank well :-)