From broken CSVs and strange encodings to region-specific quirks in dates, numbers, and currencies — this newsletter explores the messy, undocumented side of real-world data. The Missing Header helps knowledge workers, analysts, and developers make sense of data that doesn't follow the rules. Written by Stefan Fischerländer, creator of the open source CSV editor Tablecruncher, each issue offers practical tips, weird edge cases, and hard-won lessons from the wild world of everyday data handling.