1.	Introduction
The goal of this document is to define use cases to illustrate the use of the INFOD base specification interfaces in a variety of environments. The document ends with an appendix on use case patterns.
The following use cases are included:
•	NextGRID Graphical Animations Use Case
•	Car Dealer Use Case
•	3rd Party Delivery of Query Results Use Case
•	Sensor Networks Use Case

You will note that each use case follows the same structure: 
1. Defining the communities:
Community definition involves creating data vocabularies,  and property vocabularies. Data vocabularies characterize the contents of published messages. Property vocabularies characterize the entities (publishers, subscribers, consumers, and subscriptions) in the communities.    
2. Creating instances of publishers, subscribers, consumers, and subscriptions:
Instance creation involves creating publishers and associating data and property vocabularies with the publishers; creating consumers and associating property vocabularies with consumers; creating subscribers and associating property vocabularies with subscribers; creating subscriptions and associating consumers with subscriptions. The latter is achieved through the create or modify subscription operation  by applying constraints, and not through a specific associate consumer with subscriber request.  
3. Publishing
4. Consuming

When you read the use cases, please keep in mind that in most scenarios, portions of the use cases would not be repeated, e.g., creating the communities (defining the vocabularies) would be done once. Vocabularies are often re-used.