IDv1 documentation
IDv1 is a scheme for short codes. Every code is six letters or digits, and its shape tells an account from a list or an item. One address, example.com/<code>, can then open any of them, and never two at once.
| What | Shape | Example | How many |
|---|---|---|---|
| Account | two letters, four digits | Jo4712 | 27 million |
| Product | four letters, two digits | AbCd12 | 731 million |
| List | two digits, four letters | 12ABCD | 46 million |
| Item | two letters, two digits, two letters or digits that are not both digits | Ab12Cd | 1 billion |
| Event | any six letters or digits that make none of the four shapes | k3Rw9Q | 54.3 billion |
Capitals matter: Ab12Cd and ab12cd are two codes. An account’s letters come from the person’s name, and codes that spell a rude or awkward word are drawn again.
Two versions
The standard version has the four shapes, about 2.5 billion codes: enough for every person, every list and every item an app keeps. The expanded version, under Advanced, takes the 54.3 billion codes the four shapes leave free, so an app can give every event it records or every visit to it its own code, still six characters and still told apart on sight.
The scannable code
Any code can also be drawn as a strip of 16 × 4 cells and read back from a camera frame, also when it is written on paper beside other marks. A damaged cell fails the check rather than reading wrong. See The scannable code.
IDv1 has nothing to do with signing in. It names things; each app decides who may open them.
Continue with Getting started.