My pet peeve with tagging systems in general, but especially community-based tagging is false negatives. If I search using a tag, there's no guarantee at all th

My pet peeve with tagging systems in general, but especially community-based tagging is false negatives. If I search using a tag, there's no guarantee at all that it will display ALL the items that qualify for it. I'll use my favorite porn site as an example, without going into any specifics and especially linking. I just skimmed the HN Guidelines and I don't think I'm breaking any. Suppose I try the tag #bigtits. It is highly unlikely that I will get all the pictures with women who have especially large breasts. It's because no one will review all the images and verify if the tag #bigtits applies to them. That would be very time-consuming even for the most motivated individual who uses both hands for typing. So if I were into that particular fetish, I would need to try #bigtits, then #busty, then #nicerack, #slimandbusty, #ygwbt... because each tag has its proponents, and there's definitely overlap between them. You could - and I've seen non-porn sites doing that - use a program for automatic tagging, but then in my opinion you are defeating the purpose of tagging, which is grouping things by interesting categories. Machine-generated tags tend to be lifeless. As I've said it is a pet peeve of mine, and I will likely start a project or two to implement my fixes for a web framework or a static blog generator. I mean that I should have confidence that a tag has been considered for all content in the collection. Program-assisted tags can help, such as keeping track of what tags existed at the point when a picture was added. Then there are almost identical tags. #cat vs #cats, #tortoise vs #turtle, #color vs #colour. Overall, in practice, I think tagging, as usually implemented, is the most overrated feature of the Web 2.0 era.