We’ve written a lot here about Hypothesis for teachers and students, for publishers, for fact checkers, for reviewers and curators of scholarly literature, and for any individual or team that gathers and organizes pieces of web content. One constituency we haven’t addressed, though, is web developers. Annotation enlarges the web’s surface area. Formerly we could locate resources identified by billions of URLs. Now we can also locate segments defined within those billions of resources. It was already true that the emergent properties of the URL-addressable web continued to surprise me on a regular basis. Nowadays annotation delivers even more delightful surprises. Here’s the latest one, and it’s a real mind-expander.