Back in the 1990s there was that sordid episode when Microsoft Office used those other UUIDs which were based on time and a MAC address so any Office document could be tracked to what computer you used and when.
In my lost half-decade I was pursuing the dream of "Real Semantics", which, in retrospect, was a baby Cyc, not so much a master knowledge base but a system for maintaining knowledge bases for other systems that could hold several parallel knowledge bases at once. I read everything public about Cyc and also tried using DBpedia and Freebase as a prototype "master" database. Lenat strongly believed you'd get in trouble pretty quickly if you tried to make non-opaque identifiers but Wikipedia has done a pretty good job of it for 7M items, with the caveat that Wikipedia doesn't have a consistent level of modelling granularity (e.g. it is so much easier for a video game to be notable than a book, some artists have all their major songs in Wikipedia, others don't, there is no such thing as a "Ford Thunderbird" but there is a "7th generation Ford Thunderbird", etc.)
Back in the 1990s there was that sordid episode when Microsoft Office used those other UUIDs which were based on time and a MAC address so any Office document could be tracked to what computer you used and when.
In my lost half-decade I was pursuing the dream of "Real Semantics", which, in retrospect, was a baby Cyc, not so much a master knowledge base but a system for maintaining knowledge bases for other systems that could hold several parallel knowledge bases at once. I read everything public about Cyc and also tried using DBpedia and Freebase as a prototype "master" database. Lenat strongly believed you'd get in trouble pretty quickly if you tried to make non-opaque identifiers but Wikipedia has done a pretty good job of it for 7M items, with the caveat that Wikipedia doesn't have a consistent level of modelling granularity (e.g. it is so much easier for a video game to be notable than a book, some artists have all their major songs in Wikipedia, others don't, there is no such thing as a "Ford Thunderbird" but there is a "7th generation Ford Thunderbird", etc.)