[development] Unique/Random IDs and drupal

[Robert Douglass]

> Again, a driving use case is "two drupal sites that were founded  
> independently of any knowledge of each other would like to merge  
> their databases".

To me, two even more compelling use cases are:

a) sharing global taxonomy vocabularies (the countries of the world  
each have globally unique ids shared across all sites)
b) import/export. This is like the merge example from Ethan but  
perhaps a little more concrete in terms of what people are already  
doing. I could export my blog posts from one site and import them into  
another site and keep the id.
c) global user ids. I always have the same user id on every Drupal site.