# 22.00.0069: What is an ID? **URL:** \ **Category:** 22 Blog\ **Created:** [July 30, 2024, 1:02am UTC](https://forum.johnnydecimal.com/t/22-00-0069-what-is-an-id/1696 "2024-07-30T01:02:58Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![johnnydecimal](https://forum.johnnydecimal.com/user_avatar/forum.johnnydecimal.com/johnnydecimal/32/1759_2.png) [@johnnydecimal](https://forum.johnnydecimal.com/u/johnnydecimal)\ **Post date:** [July 30, 2024, 1:02am UTC](https://forum.johnnydecimal.com/t/22-00-0069-what-is-an-id/1696/1 "2024-07-30T01:02:58Z")
> **[22.00.0069 What is an ID?](https://johnnydecimal.com/20-29-communication/22-blog/22.00.0069-what-is-an-id/)** > > A fundamental Johnny.Decimal question: what is an ID, and how much should it contain? > Few days old sorry, realised I’d forgotten to cross-post here. [On the forum](https://forum.johnnydecimal.com/t/quick-start-life-admin-support-topic/1660/20), user @cobblepot raises the question of how much a Johnny.Decimal ID should contain, and whether it should contain subfolders, and if so how many. My thinking on this has changed _significantly_ over the years. The site needs a proper refresh, which will take time. It’s next on my list. Until then, this short video hopefully clarifies my thinking, and answers some of cobblepot’s questions directly. [![](https://forum.johnnydecimal.com/uploads/default/original/1X/843b5b478c47eb1514eb3c020af73bf671d480af.jpeg "What is a Johnny.Decimal ID? (2024 update)") ](https://www.youtube.com/watch?v=7vrIEl8mEl0) ---
**Author:** ![PhillyChuck](https://forum.johnnydecimal.com/letter_avatar_proxy/v4/letter/p/f14d63/32.png) [@PhillyChuck](https://forum.johnnydecimal.com/u/PhillyChuck)\ **Post date:** [July 30, 2024, 11:52am UTC](https://forum.johnnydecimal.com/t/22-00-0069-what-is-an-id/1696/2 "2024-07-30T11:52:25Z")
Interesting. Per your China example, you are essentially using numeric “sub ID’s” under a single ID. ---
**Author:** ![johnnydecimal](https://forum.johnnydecimal.com/user_avatar/forum.johnnydecimal.com/johnnydecimal/32/1759_2.png) [@johnnydecimal](https://forum.johnnydecimal.com/u/johnnydecimal)\ **Post date:** [July 30, 2024, 8:46pm UTC](https://forum.johnnydecimal.com/t/22-00-0069-what-is-an-id/1696/3 "2024-07-30T20:46:43Z")
Yes, but purely to enforce order: in this case, the natural order of planning a trip. These numbers aren’t intended to be used in a reference, like 11.52.20. (Not saying you can’t. Just that you don’t need to.) And we spaced them out in tens… ```txt 10 Planning 20 Travel documents & visas 30 Transport 40 Accommodation 50 Itineraries & schedules 60 Expenses to claim ``` _just in case_. If you do single digits you prevent the insertion of a new item. This way you can always sneak something in at `15` if you need to. Also note that, while different, this structure mirrors the ‘holiday’ template. So that gives your brain a bit of familiarity.