Hi all, Recently a few people (Tyler, Matti, myself, maybe others?) were discussing the history of missing data in the context of custom dtypes. I mentioned that there was a good write-up, but couldn't find it at the time. I just stumbled across it, it's hidden in the numpy.org repo: http://www.numpy.org/NA-overview. So hope this helps. That document further references two alternative NEPs that didn't make it into our repo: 1. https://gist.github.com/njsmith/1056379 (authors Matthew Brett, Nathaniel Smith), 2. https://gist.github.com/njsmith/1068264 (author Nathaniel Smith), as well as another summary: https://github.com/njsmith/numpy/wiki/NA-discussion-status I'd like to see the NEPs rescued, and the summary moved from the numpy.org repo (maybe into yet another NEP?). It would be best if the original authors do this, but otherwise I'm happy to do it. Thoughts? Cheers, Ralf