Since many Web applications have complete control over how paths are interpreted, the form of the path doesn't necessarily have to follow any obvious structure as far as users of your application is concerned. Here's an example:
/000251923572ax-0015
Many people would argue that such obscure references, whilst perfectly acceptable to machines, would make any application counter-intuitive and very difficult to reference. However, application developers sometimes do not want people "bookmarking" resources or functions within an application, and so such concerns don't matter to them.