| > Is Wikidata only for notable data or any data? Wikidata is only for notable data, but the notability threshold is much lower than that for Wikipedia. The criteria for notability are described at [1]. For example, we might add items for all known pathogenic genetic variants, but likely would not have an item for the fire hydrant on your street. For things not notable enough for Wikidata, interested users could install a local instance of Wikibase [2], the software that runs Wikidata. Wikidata editors and administrators determine what is notable, and have places like [3] to discuss questionable cases. > Can data be permanently, unrecoverably deleted, or is it more like Wikipedia Wikidata works like Wikipedia in that regard. Previous versions of a given item or property are almost always viewable (and recoverable) through the History tab [e.g. 4]. In extraordinary cases, like a vandal posting sensitive information about a person, data can be hidden from normal view and/or actually deleted. > Is the plan to assign a unique integer to every unit that's ever been used? Basically yes, to my understanding. How many units do you think exist? We already have items for many units, e.g. meter, micrometer, nanometer, foot, yard, bit, byte, , gigabyte, etc. I can see how this implementation might seem naive; e.g. perhaps we could represent one standard metric (like meter or byte) and handle factor conversions of scale (kilometer, millimeter, etc.) through some mechanism we don't have in place right now. Consider also asking about this on the "Contact the Development Team" page [5]. 1. https://www.wikidata.org/wiki/Wikidata:Notability 2. http://wikiba.se/ 3. https://www.wikidata.org/wiki/Wikidata:Requests_for_deletion... 4. https://www.wikidata.org/w/index.php?title=Q1&action=history 5. https://www.wikidata.org/wiki/Wikidata:Contact_the_developme... |