The mt= parameter in their URLs, when used, defeats the automatic dupe-checking, and posters who post dupes don't look first (or do so knowingly). For such peo

The mt= parameter in their URLs, when used, defeats the automatic dupe-checking, and posters who post dupes don't look first (or do so knowingly). For such people, HN appears to be a write-only interface. Sites like signalvnoise, medium, etc. add artificial tracking fragment identifiers (everything from the final hashtag on); one motivation for this is to defeat dupe detection (it's easy to code to catch that, but it hasn't been done thus far).